Yep, the snare itself.

Go to a bunch of vintage drum stores, and bang on a couple HUNDRED snares until you find 'the one.'

A few engineer/producer buddies of mine were looking for a gift for me once, and they did just that. Best present I ever got (it's a 60s Ludwig somethingorother). Here's a sample of some tracking I did with it recently in this thread: https://gearspace.com/board/showthread.php?t=93713.