I've got balls.
Spacer: Years ago I made the mistake of going to National Camera Repair school in Colorado. I bought a bunch of ball bearing balls because as you found out, they tend to vanish to the 4th dimension. A few years ago, some teacher out in North Carolina did exactly the same thing you did with his X-700. He posted a message somewhere and I answered it telling him I had little balls. I didn't know the exact size but sent him four sizes. He fixed it and asked me what I wanted for my troubles. I told him to just post a message in the school paper about how a guy helped him. A few months later, I did a search on my name and up came this article about me giving out my little balls. I contacted him and he said their school paper is now online. I thought that was sort of neat. After all, how many schools now know I have small balls? Anyway, how about you contact me at firstname.lastname@example.org and give my your address and I'll send you my little balls. You can reimburse me for the postage if you want. I have two X-700's and they are a great camera. I bought my first one new in 1985 and it has been in the repair shop once, and I still use it. It has paid for itself many times over just in memories. Anyway, if you can't find a closer source, I can't do this for everybody, but I hate to see a guy lose his balls. Again, the address is email@example.com . Later, Ric.
P.S. If you are thinking about getting into MF, check out my ad in ebay. It is the Mamiya RB67 Pro S listed under yourbasicdude.