My STARCRAFT 14 R/T has a tag affixed to the FRAME on the DRIVERS side that shows the VIN NUMBER and BUILD DATE etc... I whited it out for the photo op... I also have another sticker on the frame that shows the tire info which also has the VIN NUMBER...
I have heard it may also be stamped into the frame in a couple of places.
Also if any of the original folders are still in the trailer you might find that info on one of them... If you have the old LICENSE PLATE that can be used as well to track down the VIN NUMBER from the original TITLE...
Roy Ken