Pentax MX - Crack in Viewfinder

https://preview.redd.it/ljx1yd1hvklg1.jpg?width=1280&format=pjpg&auto=webp&s=387e14678f7d7877dfd79dbcd0e28ef3e3e9e874

Hey folks, I have a Pentax MX which has a crack in the viewfinder. Has anybody seen this before? I can't tell if it's de-silvering of the prism, or whether it's a crack in the diopter(?) or the prism itself. Does it seem consistent with any issues you've experienced before, and how hard would it be to fix? Thank you!