That's a new stamp, probably 1960's vintage. It would not be advisable to clean it. That lowers the value, and would also erase the ink under the bell.

What about it makes you think its in filthy condition? It looks fairly clean to me, with a nice patina.

I think that my camera is making it look better than it actually is.

another vote for no cleaning on that one..

mike

Do NOT clean it!!! Old K's are more valuable the more patina build-up they have. If you clean it, it will make it shiny, but it will almost assuredly sound worse and it will be less valuable if you want to sell it. In fact, many buyers won't be interested in one that looks like it has been cleaned. It takes decades for the metal to build up that natural patina - clean it and it's wasted 50 years.

The first old K I bought was in a music store in San Francisco back in the early 80s. They had about 15 to choose from. I tried them all and picked the one I liked. When I got home, I cleaned it (didn't know any better). It went from sounding sweet, to sounding crappy. Don't do it.

Yours is a "new" stamp - probably mid-late 1960s. The double/overstamp on the upper part is interesting; I've only ever seen that on the lower part.

Just noticed these stamps on the underside of the cymbal. So what I've got then is a 16 inch (41 cm) '60s K. Zildjian cymbal of medium weight. Correct?

Yeah, if you clean it, you'll lose that "medium" stamp too.

As far as the weight is concerned, they pretty much all say "medium". Of more importance is the actual weight, which can be determined using a standard postal scale.

If you look really carefully in the right light, you might also see a larger ink stamp on the underside, usually very faded.

More info on these cymbals here: http://robscott.net/cymbals/k-istanbul/

Not necessarily. That larger ink stamped "motto" was only found on some OSIVa, OSIVb, Intermediates, and older new stamps only.

1 more, no cleaning....