Thanks for the great pointers and hints. I was all over the trailer but found no VIN except for the manufacturer's sticker inside the closet door. I needed the VIN because the trailer was to be registered in my home province (BC) but the trailer was last registered in Alberta. The insurance/ICBC rep. sighted the VIN in on the manufacturer's sticker and, because it more-or-less matched the VIN on the registration
(I think extra digits were added in Alberta to fit the computer system), they accepted the registration
and followed up with their processes to register it in BC. Towed it home with shiny new BC plate and am now looking forward to getting it highway ready
Next step, to the local RV mechanic to give it a look-see for old-readiness. Then, the cleaning and rebuilding will begin!