Anybody know what fits here or where they sell the transmission for a snapper rear engine rider?

[semimechanicman]

I have a snapper 1438h and I have discovered that it is a very rare mower. Unfortunately the mower would not move when I made it start and took the transmission out and saw many broken pieces. I would like to have this mower and not just scrap it since it is rare so does anyone know where there is one for it? Can another transmission fit on the mower? I wouldn’t care if it is different as long as it fits in.

Transmission: Peerless 205-043D