Figured I'd post a follow-up with my latest info... Comrad raised a very valid concern for the usage of cigar boxes with guns (or any other metal pieces).
There is an online "ask the wood expert" site, maintained by Oregon State University (I guess they have a doctoral program dealing with wood usage). I posted a question regarding the safety of this and any possible humidity concerns.
Received a reply, wherein the guy said these boxes would be very safe. Seems the wood is chosen because it has insect repellent properties (the preferred wood for a cigar box is "spanish cedar", which keeps things as bug-free as "regular" cedar but doesn't have the same strong scent).
It has no magical humidity properties, but instead, absorbs/releases humidity to maintain a balance with the air in the environment.
In fact, he said that the box would dry out the cigars, and that people would have to periodically place damp sponges inside, to counteract that.
The exterior is finished, the interior is unfinished wood- so if you wanted to make sure they're "dry", simply leave the boxes open a couple days, in a dry environment (like inside a house with the AC running). If you still have concerns (like if your house is too moist), he said to place a dessicant inside with the gun, and as you keep the box closed, the air inside the box would become much drier than the air outside.
Of note, he also said the wood will evenly absorb and hold moisture- if you were to place a couple drops of water on the unfinished interior, that water would be spread throughout the entire piece of wood, and not stay in that one spot. Similarly, placing a gun or other object will not cause water to condense at the point of contact, it will remain evenly dispersed throughout the fibers.
Also of note- finished or sealed wood would not have the same properties, it would prevent the wood from absorbing. So don't place a gun directly onto a sealed piece of wood, as there is the potential that water would condense on the surface, and lead to rusting issues.