If they are very old and have not cracked or show problems yet, guessing they will not in the future unless you expose them to big/fast changes in humidity.

Dry shells are a good thing...they will resonate more. Like the previous poster said, don't expose them to the elements too much but otherwise they should last many more years to come.

Cuttle

Ya might try Natural Bees wax,..I use it on the inside of mine to keep moisture out. Don`t be alarmed by how dark and wet it looks after apply`n it,..after 24 hours, it looks like you did nothing, it dries completely clear and has no sheen. I use a white crayon on the edges. Try it on a scrap wood to see if ya like it.

If it worries you, you can always try one of those acoustic guitar humidifier things that you put in the case....

I am just inexperienced and would rather ask now than be sorry later. Any helpful tips are appreciated in any area of the vintage drum field!

It is a good question you've asked. A lot of people wonder about this one. There are several things you can do. MI is cold and has lots of dehumidifiers. The houses tend to run warm and dry. The air tends to run dry. Try to keep them out of the elements and away from basements.