I don't want to be "that guy", but..............
For those of you that have cymbals that only fit 1/4" or 6mm tilters, why not just enlarge the hole in your cymbal?
Now I know altering any kind of vintage cymbal, your prized possession, is taboo around here, but I have done it (gasp!) on my vintage cymbals and it does not affect the sound at all. My thought has always been, what good is a vintage cymbal (that I assume you love the sound of and want to play as often as possible) if you can only use it on certain stands or in certain setups?
Virtually all cymbal stands being made these days have 8mm tilters, and virtually all accessories (sleeves, wingnuts, felts, specialty wingnuts etc.) are all for 8mm stands. And for good reason: They are more durable, bigger threads = less chance of stripping or damage, and the thicker sleeves keep the cymbal more supported while still allowing for plenty of freedom of movement in the cymbal.
I have some Ludwig and MIJ vintage flat base stands that have the 1/4" or 6mm tilter threading. I use 8mm sleeves on them, just because I like the way the cymbal "feels" and moves on an 8mm tilter. And if it wears out, I can find a new one virtually anywhere. Again, I realize altering vintage cymbals (or any vintage drum or cymbal) is taboo, but if you are only making the center hole just a minuscule bigger, where's the harm in that? It's not like you're routing out a 1/2" hole or even putting rivets in it.
Please understand, I am not being critical of anyone at all, I just have never understood that logic. It's like having a favorite snare that you love to play, but it only fits on 5% of the stands out there; with the other 95% it's unusable. To me, having to search for certain stands just to be able to play your cymbal is backwards logic. The cymbal should fit the stand, the stand shouldn't have to fit the cymbal.