Possible purchase

Hang on fellas
I have seen flywheels that only "looked" cracked, but in fact were not.
If the price is right, I would buy it anyway, tear into it, and verify that the "crack" is in fact a crack; then move forward.
If it really is cracked, now you have it in your grimy hands and can figure out exactly what you need, or how to adapt something. Hot Rodding is all about making it work.