Help needed identifying Shower knob

[platnumdesi01]

Hi everyone - We bought a condo and are having the toughest time trying to replace the shower knob. After driving all over the area, the folks at the local hardware said they haven't seen one of these in years. It's just hard to believe that it cannot be replaced. It has a SQUARE shape and most new ones are round. I have attached pictures. One of our handyman said that thing the knob goes into will have to be entirely replaced and he will have to cut the tiles. I would hate to do that

Any help would be fantastic as we have burned many cycles searching. THANKS again, glad I found this forum!

 

[platnumdesi01]

night time bump