Ruby takes of her shirt. Since she's up there and there's no one to see her, she shouldn't terribly mind. Then let Tom fill up the shirt with lots of junk, along with the access card. If needed (which is probably likely), Ruby can drop down junk for Tom to fill it with.
Knit shirt with junk+access card, and then throw it up again, like a ball.
All that wire, the treasure chest, the otherwise unusable remains of the can (even if it's just utter scrap, no amount of weight has just "disappeared"), the letter opener and the can opener together really must pack enough weight.