660 back brake mistake

https://2img.net/h/i1283.photobucket.com/albums/a556/rhino686/A3BBA825-DD8C-440C-AF83-0787AFA19C1C-142-000000026F369818_zpsc7c0c4de.jpg

Dont make my mistake on the 04 660 tje back brake piston screws in insted of pressing in with a c clamp. I didnt know this untill i found inside the piston i flatened the threads if you can see in the picture. Im not sure if i cam buy just that pice or need a new calaper. I may sound stupid but im just putting this up in case somone hasnt changed brakes on the 660 so they dont make the mistake i did

could u run a tap in it to clean up threads  may be enough to make it work , if not u may need a new one

Idk if they make a tap for that kind of threads or where to find it