Here is an interesting presentation put out by my friend David Albert. It concentrates on Thompsons but is applicable to virtually any model of collectable. This was in response to another friend who stored his original, Savage Thompson in a reproduction Cavalry Case in his safe and ended up rusting his beautiful, original TSMG. Aside from the fact that canvas captures moisture, many of these cheap, foreign reproductions have harmful chemicals in the fibers which will do a serious number on a gun's finish.
http://www.sturmgewehr.com/dalbert/T...ure%202010.pdf