Hi Bass,
Do not purchase a clutch half as yet.
Sadly more bad news is on the horizon.
From where I'm sitting it looks like those rails are stress fractured in many directions. Your photos are not accurate enough as I really should've said take vertical shots of the rails (looking straight down). Anyway if someone has already taking to the rail with a welder on the vertical plane of the rail you can bet your bottom dollar that there are fractures all through the horizontal section where the engine bolts down on to. This will have to be repaired by a competent welder (trades person)
or it will become nothing more than a corkscrew that's totally useless.
Just hitting those fractures with a welder will induce way too much heat and the end result will make it curtains, thus a competent tradesman will know all about heat and shrinkage etc.
Please can you put up some directly from above and close up shots around the engine mount holes.
Speak soon.
Cheers,
BB