Well- either I broke it removing a stuck cannon pinion or it was already broken but the center jewel on a Longines 10L movement I am working on is destroyed. I am new to watch repair- how do I find a replacement? What size? I have no idea where to even begin. Thanks. Marc

Let me be a little more exact. I have a jeweling and staking set. I have never used them yet but am ready to try! I know you can buy replacements- for example here:

http://www.dashto.com/newlists...hermaterials.htm#037

What I don't know is how to find out 'which' jewel to buy? Size?- then how to measure?