If you know the manufacturer of the towel bars, you might want to try contacting them. Even if it's not a current item, the mounting hardware may still be available. Good luck... that's frustrating!

I take pseudoephedrine, usually one 30mg tablet at a time works, and I start taking it as soon as I suspect anything. So far it's worked. The new stuff (phenylephrine) sends my heart rate soaring, so I can't take it. I don't care if they think I'm making meth in the basement. I don't know what I'll do if they ever decide to take pseudoephedrine off the market, I'm allergic to the most useful antibiotics, as well as Tylenol (acetaminophen), so I'm obsessive about heading off sinus infections. I don't take any combination medicines any more, they have too much useless stuff that I don't need. If I need the individual ingredients, I can buy the generic form for many, many dollars less than the combination meds.

I don't know if it is comparable at all but I had to replace my broken fixtures and the did it through the back where it is attached to the pipes anyway. Since you have relatively small footprint fixtures, any disturbance to the tiles might be able to be handled with some kind of matching metal plate. I just hired plumbers and any part of the wall now showing (i.e. isn't covered by metal parts) doesn't have holes so I assume they found fixtures that more or less retrofitted to the holes. I know that they attempted to just find internal replacement mechanisms for a repair but they couldn't so the front part also had to be taken out. I am completely a lay person with only the most basic understanding and no knowledge of plumbing nomenclature - all I know is that they went in from the back and then had to retro fit something to the front. Mine was a hideous fiberglass tub/shower enclosure but the principle would be the same in terms of not having a gaping hole where a different fixture was installed.

Here we are https://www.houzz.com/photos/custom-craftsman-home-exterior-craftsman-exterior-chicago-phvw-vp~624882