Here are some preliminary choices:

Floor tile (Emser Bombay Satara)

Vanity (this is Kraftmaid's Momentum Frontier and is approximately what I want, but possibly in natural maple, and probably not Kraftmaid). The existing vanity is 36 inches and there is not space for much more. It is important to me to have either a cabinet door or a deep drawer for the wastebasket, because there isn't floor space and I would rather conceal it anyway.

Sink faucet (Grohe)

You do you, but I don’t feel that looks like bathroom tile. Too dark, too entry feeling. Pictures of your bathroom? Rest of house?

Thanks for the reply! I see what you mean about the tile. It won't be the eventual choice in any case, because the tiles are too large for the area. However, I do think that I want a slate look, not a marble or granite look.

The trouble with a complete redo is that everything has to be chosen before it's possible to choose anything. For example, the floor colors depend partly on the finish of the cabinets.

No pictures, because they would only show what I'm trying to remove, but here's a floor plan.

Just get real slate.

Just get real slate.

Did you read my first post?

Slate is not high maintenance. I don’t know where you got that idea. I have 60 year old slate that only needs swiffering.

Less ungrateful snark over eyes glazing over your novella and the good FREE ADVICE gets you further around here. Most people will just click Back and move on. More bullet points with pictures and diagrams gets you better responses. Or you can always hire a paid designer to give you the same good advice.

The original MCM is highly desirable and should be restored. https://retrorenovation.com/

You will get more feedback if you post existing pics since people love to be critical it gives them something to tear apart! : 0 I like your sink base and single handle faucet. I also chose a stone looking tile and wanted a stone look with a smoother finish than real stone. The tile I chose came in whitish/beigeish/brownish choices. Which of those shades is personal choice. So if you are drawn to brown, go for it! I went for the in between beige. Your home sounds very interesting. Hopefully you won't get scared off by mean posters and will update us with your progress and keep posting for feedback!

The original MCM is highly desirable and should be restored.

Nothing in this room is original MCM except the narrow built-in shelf and door unit (just inside the hall door) and its knobs. Everything else was done cheaply 12-15 years ago in Victorian style.

But this is something that I'm keeping in mind with regard to the kitchen, where the cabinets are original. I need a different configuration there to install a dishwasher, but one possibility is just to replace the last cabinet in the row with a wider one, reusing the original end panel. OTOH, the countertop needs to be replaced, and hewing to the original MCM design would mandate laminate again.

Less ungrateful snark over eyes glazing over your novella and the good
FREE ADVICE gets you further around here. Most people will just click
Back and move on. More bullet points with pictures and diagrams gets
you better responses

I admit that I wrote too much and that it's hard to follow. I appreciated comments about the examples and maybe I leaped prematurely to the conclusion that I was hearing from purists who abhor anything that isn't 100% genuine.

Slate is not high maintenance. I don’t know where you got that idea. I have 60 year old slate that only needs swiffering.

I'd like to know more about your experience with it, especially if it's a bathroom floor. Slate is in period and there is slate in the front entry. Some of the stone vendors include slate in their warning about other natural stone -- that it needs periodic resealing (the 68-year-old slate in the entry is in good condition and I doubt that it was ever resealed), and that any spills must be wiped up within 2-3 seconds. Maybe that's just CYA on their part.

I recently redid a bathroom that had originally been done entirely in Indian slate--shower, floor, and tub surround. I ended up putting a porcelain that looks like slate in the non-shower part of the floor. In retrospect, I'm kind of surprised because I grew to loathe the real slate over time. It's a hateful material in a shower.

As for the rest of it--forgive me, but you're overthinking all of it and it's going to drive you nuts. I know because I've been there, both myself and alongside clients who desperately need direction.

Find someone local who can help you with finishes. Even if you're not moving anything, you need someone to help you make choices. Honestly, I was interested by the story about your house, and then the "Scandinavian Spa" idea sounded intriguing...then the images you posted were a complete surprise, and not in a good way. Let go of what you don't like about what's there. Let go of the stories about the squabbling former owners. Let go of your fears about stone (that doesn't mean you have to use it!) Get with someone who can help you make this project fun for you. That's my advice. Renovation is hard, and it sounds like even the thought of this one is making you miserable.

Also, I really would like to see what that bathroom looks like, but it's for another thread....good luck to you.

p.s. and FWIW, for the rest of my bathroom, I chose plenty of natural stone. Even (gasp) marble! It's beautiful and I love it and it requires nothing special that I find bothersome. Find what you love. A good designer who knows the good tile shop is an excellent place to start.

We are adding a bath and went for a larger version of this floating vanity - ours isn't installed yet, but I really like the idea of making it easier to clean the floors (and that's a good idea if you're hoping to age in place!). You do need extra support, so it's worth being sure of that before choosing a floating vanity.

I like the look of a floating vanity - the Ikea Godmorgon would be fine with me except that neither is this a DIY job nor is there an Ikea store anywhere near here. A truly floating vanity may not be feasible anyway, because the plumbing runs down through the floor. On the other hand,the pipes are close to the wall, and because the room is so small, a box enclosing them would not be visible (nor would the pipes themselves, I realize).

it will bum you out if you redo your bathroom and sell your house only to find they've ripped out your new bathroom to do what they want with it

I would probably never know! The seller of this house and I never met, and if I were to sell the house within just a few years it would be to move out of the area. In practical terms houses in the immediate neighborhood go to first-time buyers who are financially stretched and can't afford to make any large changes for a while.

While I love the idea of putting in a retro bathroom

I might feel differently if there were anything original to work with beyond the door and window frames, and if the flowering of mid-century design had reached bathrooms by 1951. I have some pictures of original mid-century bathrooms that I like, but they are all from houses built about a decade later. Some of the design elements in them have now come to be considered fresh and new.

Thanks for your comments.