Dick,
just wanted to clarify, still a great, informative article.
I made lots of errors, typos, and mistakes in writing the T99 Arisaka book, I caught a lot of them; but still find one occasionally. Once you read it the way you "meant" it to be, one can never find even the obvious error- or at least I can't.
Proof readers and editors don't help much on technical points- as they just don't know the difference!