WOW... happy for you!

The reason he put for contact sheets is i don't think that paper was considered top of the line, so it wouldn't make sense to put your best print on it so contact sheets of negatives was his use for it... Fiber is more along those lines....

As for the IV FB from Ilford, i know that paper is pretty robust, and so is probably still good. (considering it goes from about .50 -$1 per sheet 8x10, any amount of this is good)
The G2 is pretty ancient by paper standards, but this is when we find out how well stored it has been.
the rest i don't know of.

i think the recommendation is to get a piece of paper from all of these packs, and develop each one for the standard 2-3 minutes and see if it greys/fogs up... If it doesn't that means it's still plenty good, if it does, as was mentioned earlier, you can try and save the paper, but i wouldn't print my best prints on it. Also, even if it doesn't fog, you have to consider that it might not print as intended after so long of being in storage (contrast issues).

On another note, congrats again on your awesome find, i similarly received plenty of stuff as well as a blessing from a photographer gone all digital all for the sum price of 100 as well (sans paper). Also consider each pack of WORKING paper as a return from your $100 bucks as it's probably the most costly part of darkroom work.