Without sounding like a bad comedian, there are a lot of things with vintage drums (and used drums in general) that make you say "Why is it that...........?" or "Did you ever notice that.................?" or "How Come It's Always.......................?".
Here's a thread to share common observations, frustrations, humor etc. about used/vintage drums. I'll start:
Why is it, that on seemingly every MIJ kit I have ever seen, that there are always water stains on the interior of the bass drum and/or floor tom?
How come that on many used kits we come across, vital pieces of the kit are constantly missing? Like on vintage kits with the straight, solid rod spurs. So many times they are missing! How do you misplace the spurs? You can't play the bass drum without them! Or, on more modern bass drums with the rotating fold out spurs, the threaded rubber foot that either hides or exposes the spike is notoriously missing. Who is losing this stuff? Another item that is perpetually missing is the cymbal L-arm!
Did you ever notice that the more rare a wrap is, the more likely the bass drum hoop inlay is missing?