It doesn't matter if the uniforms have to be "specific." You can't take a tax deduction for donating a "partial interest" in property. That means you can't take a deduction for allowing a charity to use an item of property, or borrow an item of property, or sharing an item of property. You can only deduct the donation of an item if you donate *full ownership* to the charity -- full ownership means the charity can keep the uniforms, assign them to different reenactors, sell them or even destroy them, all without permission of your husband or son.
If your husband and son moved away so it was no longer practical to be in the group and let the group keep the uniforms when they left, it would be a donation at that time (but only the fair market value, not what it cost them over the years to create and maintain).
But as long as they own their own uniforms and gear, you can't claim a deduction for donating the use of the uniforms at events.
Travel and other expenses have to be in accordance with the rules in publication 526 as linked below.
