I don't know the answer to your question but like you would like to hear the answers because I have similar question. why was't your question answered? it'a good one.

The simpler, and cleaner..........the better. Think geometry. Skip the curls and squiggles

Thanks! I have seen these often now. I'm putting in door and I like your answer. I guess they sell them everywhere. Thanks for the pictures too.

For this, let’s revisit what shaker doors are. Minimalism is the key characteristic of shaker-style doors and cabinetry. So, the door handles you choose shouldn’t disturb the minimalist aesthetic. The best suggestion for this would be simple and clean door handles that blend in the geometry and aesthetics well.

On the door facing outwards? Match either the glass bathroom knob directly opposite or the other knobs in the house. Reproductions or vintage salvage (architectural salvage, eBay, Etsy, antique shops....)

Because your doors are not in a vacuum; match up with what exists in the rest of the house & ignore the modern interpretations of what goes with Shaker.

Unless, of course, you just want to change all of the other existing hdwe in the house.

Try Nostalgic Warehouse, they may have a close match to your old, yet fit modern doors.