Spent an hour and half this week just opening boxes in the warehouse..
Make a long story short I found a correct sized wheel with a wrong hub offset... settled on a fairly common blower motor assembly that fit in the housing. After centering the wheel in the bore, drilled some holes and were good to go.
Used 3m strip caulk around the heater core (evidence it was there once before) and on all sealing joints.
Working on mounting, plumbing and the defroster ducts this weekend..