I don't like the fact that both sides of that mold don't have at least one set of the same numbers as the other side....if I understood ,this right.
The industry standard for cutting cherries to make the mold is through the use of a 20:1 alloy, commonly known as Lyman #2 alloy. Both sides of a mold are stamp with the same identifying number so the can be clean, oiled and reassembled properly.
If Swamp has the .610 mold and a ball cast from the "other" mold but doesn't have a Micrometer or a Caliper, simply drop one casting in the other mold...if it's larger it won't go in, if it's smaller and the mold will close ,you can hear it "thunk" around a little bit, since lead ball don't really rattle.
Then, of course, you just fire up the pot and cast some and see first hand what you got.
The AV is for "A" Vendor...For almost twenty five years, until 2002, the A-Vendor for Lyman was Bill Grady of El Paso Texas. (and, I understand that Walt Melander, also of El Paso Texas, once held a "V" designation with Lyman too, before he became world famous with his own designs).
The BV is for "B" vendor...another person / small machine shop that makes molds on contract for Lyman.
The CV is the same thing, and on and on it goes.....
This is a system that was started by John Barlow back in the days when Lyman was still called the "Ideal" bullet & mold company.
We have an old-timer from the Cast Bullet Association that drops in every once in awhile.
His first name is Doug, but for the life of me I can't remember his last name. I hope he sees this and offers some help on this subject. Doug is a very knowledgeable person and a wonderful writer, I will see if I can't round him up.
I feel sure you'll enjoy his writings.
There was a time with many of the older Lyman / Ideal molds you could read the bullet size and the weight of the bullet the mold drop, ie 600437 meant the size was .600 and the ball would weigh 437gr, with the use of #2 alloy of course.
Then we went to a system where the first three numbers were the size, and last three represented the "top-punch" for sizing"
Then we went to a computerized system that supposedly increased production, and those numbers mean little of anything to the person buying, trading, or selling anymore.
Uncle Russ...