Unfortunately, I don't think that marking drums and cymbals will do much good.
Drums don't have to be registered like a car after they are bought used.
You would have to find the ad where your stolen drums are being sold, Identify them from the ad pics, and alert and enlist enforcement to assist you in recovery.
If I was a drum thief, all that I would have to do is remove the ID marks and it would be hard to prove that they were stolen at all.
Many thief's simply sell the equipment without placing an ad at all.
One of the biggest mistakes that I hear musicians make is talking in a club with other musicians about their latest gear and such so that others in the club can hear.
Say I'm just a guy in a club. I just heard you talk to your friend about your $4000 drums and $400 pedals. I didn't even know that this stuff was so valuable until now!
You just tempted me to steal!
I always leave my cymbals in the bag until the kit is on stage and Im about to play. I always bag the cymbals on stage when I finish. I carry them to a safe location first.
I never talk about any of the gear that is on stage where others can hear.