if you don't have a ***le and a VIN plate attached to your firewall you likely will have too...other than that, not sure about NY law...
Model T numbers are on the engine, I've seen them done home made and by buying a do***ent for "display".
hypothetically speaking... as long as the car you are building has a VIN number stamped somewhere on it, you could take a rubbing (or better yet a picture of said VIN number) to the DMV. fill out the neccessary paperwork and you got yourself an open registration. Seriously though, how do these guys building gl*** bodies, aftermarket ch***is get their stuff registered as '32 - '34 Fords??? Henry never put VINs on fibergl*** cars. Know what I'm sayin'