I can guess at the weight of my trailer, but without taking it to a weighbridge I don't know. It was 914kg originally, but the rear ramp, floor and partition have all been changed at some point.
I only recently found the date of manufacture plate too, although I knew it had to have been made before 1989, as it doesn't have an auto-reverse hitch. It's actually dated 1976!
I would have thought it's easier with newer trailers, as the plates shouldn't be so worn as to be unreadable and less of the structure is likely to have been replaced with non-original parts.
As for the sizes - just how hard is it to use a tape measure??!!