When the motor has seized and the input shaft is the type that has the circlip holding it in, You cannot get the bellhousing off, because the damper won't rotate to get to the bolts holding the damper to flywheel. Bellhousing has dowelpins so can't even rotate the housing...
I know this sounds extreme or crazy, but for the cost of a replacement bellhousing I guess a guy could just cut off the tail shaft portion of the bell housing with a 5" electric cut off wheel, cut through the housing and the shaft, essentially cut the last bearing portion off and pull the housing leaving the disc and shaft connected to the starter plate?