Depends on your definition of classic. My thread, which silvam mentioned, is mostly 80's stuff, with a bit of 70s and early 90s mixed in. The retro thread also might have some older stuff.
http://www.ootpdevelopments.com/boar...-uniforms.html
I found a few loose ones that I'm using now for my own 1944-? Eastern League in this thread. Williamsport Grays, Albany Senators, Hartford Chiefs, Utica Blue Sox, and Binghamton Triplets:
http://www.ootpdevelopments.com/boar...-uniforms.html