In Colorado they have a "Rebuilt from Salvage" titleling process, check out:
http://www.colorado.gov/cs/Satellite/Revenue-MV/RMV/1186648383344Wisconsin might have something similar.
If not, find someone you REALLY trust in Colorado to assist you, just make sure you have any/all paperwork proving it was sold to a scrap yard.
G/F bought a stock trailer from Montana, when we got it back here we had to get a "VIN Inspector" to "offically" read the VIN in order to register it here.
There was not a VIN to be found on the trailer. Hmmmm

But she got it registered as "home built" and they issued a rivet on sticker with numbers.
Had to do the same with a Harbor Fright trailer also.
Good luck