How about being able to make the obvious thing? Chests. It could require X wood of at least Y size, and an ingot or two. Skill (Carpentry AND blacksmith) would determine how much the chest could hold, and wood/ingot type could decide weight.... And You should be able to featherweight it too. Also, of course, it would be like store chests, without a lock until a lock is installed.

Also, I think fighters should get bash lock back. But bashing the lock on a chest created using Laen should be near impossible, or at least never take less than an hour. Similarly for vault doors.

Oh, on that note, tinker locks should require an ingot to do. Installing using a laen ingot on a vault door = near unbashable. Iron on a wood door = not so impossible.

*rambles on*