Data stickers (with VIN and tire sizes) have been traditionally placed on the drivers side sidewall at the front lower corner of the trailer. Typically the stickers fade out or peel off over time, so fair chance there is no sticker left on yours given the age.
Sometimes the sticker may have been placed on the drivers side of the tongue A frame and with some of those it may be a aluminum plate riveted in place.
The serial number (which on older trailers was the VIN) or VIN is often stamped in to the top or side of the tongue A frame and sometimes will be stamped on a aluminum tag and riveted to the tongue A frame.
Not sure what info you seek that will be on the sticker, typical info is VIN, tire size, air pressure for the tire size and GVWR..
Old ones like yours did not list unladen weight, tongue weight.
For GVWR you can count the lugs on your tire rims, 4 bolts you have axles of 3,000 lbs or less, 5 bolts you have axles of 3,500 lbs and 6 bolts you have axles of 5,000 lbs each..
Add up the axles and you will be in the ball park for GVWR and the trailer unladen weight should be less than GVWR..
To get unladen weight take it to a scale and get it weighed..
Many of the trailers made after 2000 may have an additional label in one of the kitchen cabinets as eventually someone figured out that stickers on the outside fade away..
