As an Allmand 23 owner, I'll put in my 2 cents.
For a look at Allmand boats go to http://allmandboats.com/history.htm
and you'll get links to old brochures and some company background.
The hulls are built like the proverbial brick outhouse, which is one reason for Allmand's demise...they built them TOO good. Compare them with Bertram and other top of the line boats in terms of build quality. Below the bonded hull liner is a egg crate like framework of stiffeners, stringers and cross braces all made of hat channel fiberglass. The bonded hull liner creates floatation so don't poke a lot of holes in the deck if you can avoid it. No wood on the boat except for the transom. Any boat of this age should have the transom checked for rot or wetness. I had to have mine repaired.
I have the Ticonderoga, a flybridge version of your boat. I have completely gutted it and rebuilt everything with all new. Engine, drive, wiring, electric potty, holding tank, instruments, hydraulic steering, windlass etc. I think it's worthwhile to redo the boat as it is as nice a hull as you can find.
Good luck with the old Ford. Hope you can get it going. As to replacing parts, generally speaking if it's made of rubber replace it. If it has the old OMC Stringer drive, you may consider updating it with a newer drive at some point in the future. Go2marine.com has a good online parts catalog with pictures of parts.