Other improvisational weapons/tools:
Icicles are useful as daggers,
Bag Of Holding filled with copper pieces used by chucking the contents at foes, (by strolen)
sleeves make useful garrotes. Ya can't cut anyone's neck, but you sure can choke 'em!
Flaming Logs make great clubs, (any Barbarians out there?)
and Bee hives are very effective when thrown at a mob of enemies. :-)
A casual remark by one of the party about something met on a previous adventure leads to a summons to and grilling by the Mages' Guild (or equivalent), probably resulting in an expedition back to that area to recover the things for 'study' by the Guild. The party's presence will be 'requested' for this expedition.