The 45 feederhouse was offered by Deere after 45 production had ceased. The ones from newer combines won't be the right width. They are out there, though, as many older combines were equipped to work with the newer heads. I have one on our 105, and it has been used with a 1993 643 head.
I have a 435W head that would be good for parts, it is in the shed, and I'd like the space. I don't know what parts you need, an Wis. is a long way from you.