Congrats. Sounds like a nice piece. And you are correct, Turk Mausers, not just the 93, are seldom found with matching numbers.
Don't know, except to say I've seen other numbers in the same position on these through the years. I have an unconverted 93, with the original serial on the right side of the ring, with '888' where your 93 is. Nice rifle you got there.What do you make of the "93" stamped on the receiver ring?