Beg to differ, but the engraved stamp, picture 3 of all shown on your O.P. is of a later 80's to 90's logo, the "O" on CO is capitalized. That was done on older cymbals, not a "Hollow" ink logo Zildjian. This is the type of logo for "Hollow" ink logo:
Backbeatkeeper,
I have 3 "Hollow" ink logo cymbals - 14" hi hats, 16" crash and 18" crash. The 14" hi hats and the 18" crash have the older Co stamp (lowercase o), but the 16" crash has the CO stamp so there was a transition period where the later stamp (CO) was used with the "Hollow" ink logo. That would probably put these at late 1970's to early 1980's with the transition to the solid ink logo and CO stamp in the early to mid 1980's. I also have a 16" crash and 20" ride with that configuration as well that I picked up used in 1988/1989.
Here are pictures of the 16" crash stamp and hollow ink logo.
[IMG]http://i802.photobucket.com/albums/yy309/HerronScott/Zildjian%20Cymbals/100_1019.jpg[/IMG]
[IMG]http://i802.photobucket.com/albums/yy309/HerronScott/Zildjian%20Cymbals/100_1024.jpg[/IMG]
Scott