Sorry, tayport is right...my bad.
Do not buy anything until you speak to him and do some checks.
As i said, I think that has hit something so gearbox may be compromised, i.e bent prop shaft etc. The motor will need to be gone over with a fine tooth comb to make sure you end up with a usable motor after doing this. Don't assume the rest is okay, check it. Compression, corrosion, electrics , gearbox runout etc
If you are handy with spanners and do the work yourself it is probably worth fixing depending on the price of the mid section. You will also need gaskets for head and may as well change the mounts at same time so probably worth you factor those in along with normal service items.