I've got a 10" K splash with a radial crack in the bell. I carefully drilled the ends of the crack with a 1/16" bit and it's held up just fine. Use a magnifying glass or jeweler's loupe to find the actual end of the crack, as is might extend past the obvious end, then mark it with a sharp pencil or some such before drilling.
I have a 10" Zildjian splash that I mostly played with my hand that got cracks around the hole. I took it to an artistic welding friend to attempt a brazing repair. He has the tiny tips that focused a minimal amount of heat to the smallest area while I kept things cool with a mist sprayer. A much larger area around the hole started crumbling and cracking so he stopped immediately. By the time we finished breaking and filing away the softened and brittle stuff and got to metal that hadn't been damaged and was still solid, I had a cymbal with about a 2" hole. I am so glad I didn't and would now never attempt that with a more valuable cymbal. IMHO drilling is safest but I would still consult an expert in old Zildjians. On drumforum there is a cymbal geek/wizard named zenstat. Am sure he would love to see/know/share his opinion on your cymbal and tell you more about it than you could imagine. Myself, I would not drill it, would play it carefully and cherish it for the special mojo it must surely have.