http://www.gizex.com/vintage-instruments/
14" HH (med? 1967)
15" HH (heavy bottom used as crash, no mate 1965)
15" HH (regular 1965)
18" Ride (lines from aluminum sizzle attachment 1965)
20" Ride Keyhole and repaired (found this way 1967)
Close-up of the stamps for each of these, which I believe are all the same. 18" ride is just a little lighter impression than the others. (opinion) :)
The two marked 1967 were acquired used that year. Marked 1965 I bought new.