Nice. TPU might work. What did you model it in?
Blender. Super simple little model. I can share the stl, with the caveat that it's probably crap.
I’d be a bit worried with those that there would be too much flexing there and that it could damage the new parts or worse, cause the bezel to stress crack. I just feel like there’s a reason the originals were rubber.
How do they feel to you?
I'm not sure what you mean about the flexing. It seems to me that whole area is pretty stable, no? Since everything at that site is kept in place by the screw. I'm not an engineer though, so...
But the fit is not so tight that I'm concerned about outward pressure much, if at all (fwiw - again, not an engineer). I did a few test prints at different sizes and ended on a 6mm diameter which feels not so tight that you have to use really any effort to fit, not so loose that it will fall out. I think too - in this case, with the PLA - the ridges from the print interface nicely with the rough texture of the PB's plastic and help keep it in place. i can easily pry it out with a fingernail.
All that said, this is all just for testing at this point and not intended to be a permanent solution. I will still try this with TPU once I get a higher-resolution print - which I probably should by tweaking the print settings. I'm not very experienced with 3D printing, so lots of iterations are in order.