Question in regards to '25 stash slots'

[Tootex]

My son loves to play AL but even more so when using my rogue as she clears his maps extremely quick for him lol. He knows the rules - no trading unless me (daddy) is present, no begging (not that he has any need to), show respect, courtesy, politeness and thanks. Today he purchased the 25 stash slot kit (my stash is jam packed to the brim) with story tokens not realising that my stash is already maxed out. These kits are 'stashable for your other characters but not tradeable'!! I can't stash for my other toons as they all use the same maxed out stash house and I can't sell it as it's not tradeable so what other options do I have? I'd gift them to a player in need if it was possible