Thanks guys for your interest!
As for the load rating, I could find none.
I've said this in the thread for the 100/LX470 ladders, but I have sold a couple of ladders so far (for the 80) and neither one of the members have reported any problems. But they are not exactly huge either.
I know that is very vague, if I weighed 200 lbs, I don't think I woudl consider getting one (you should not be getting up on any ladder for the 80 with that kind of mass, unless mounted on the bumper or something ;p ). Sorry that I can't give you a definitive number.
Also there is no drilling required for the 80 ladders, unlike the ones for 100.
I have put them together (sorta) and took some pics for your viewing pleasure.
I have, however, discovered one disturbing thing though. The hooks that hook onto the top part of the tailgate seem to have R/L sides, rather than both being identical (at least with the other two, as well as what it says in the instruction). But the when I was opening the OEM hooks, I saw "R" when in fact the wrapper said "L" on it.
You can definitely see in the pictures that the right hooks are placed a bit higher than the left, except on the OEM one. But I'm not sure if I recall noticing the difference when I had the one that I sold to Tooth Fairy (I'd ask him, but have not seen him around lately. Maybe busy extinguishing fire

).
I believe it depends largely on what part of the tailgate you want to mount it. If you mount where the right side and the left side are pretty much level, then I don't think it'll be an issue. But don't take my word for it. I wish I could get it clarified and get a new hook for it, but I'm afraid that they no longer have them in stock (they don't make optional parts for too long).
Anyway, here are the pics.
I hope these give you some ideas.
Mot