Interesting combination of ink on that one Sean. It's earlier than 1990s, not that it matters that much.
The solid ZILDJIAN on the bottom (without a ®) is 1982-ish. But a cymbal with the solid ZILDJIAN on the bottom usually has a solid ZILDJIAN on the top as well. Yours doesn't. Unusual. Maybe it was removed, but in such a way that the model ink was left in good condition?
The model ink "MEDIUM THIN CRASH" doesn't have the diameter written underneath it, which came in at about the same time (1982-ish). Unusual again. Why would somebody remove just the diameter info and preserve the "MEDIUM THIN CRASH"?
This has me wondering if that's a Hollow Ink (aka Hollow Logo) from the 1978-80 period, and somebody filled in the hollow lettering on the bottom. The way that bottom ZILDJIAN has worn makes me wonder. So does the 70s looking hammering on the top, and the look of the bottom. And it has what we call the 70s die stamp, although use of the 70s die stamp seems to have lasted well past the 1970s from what I can tell so far.