I have recently acquired a model 10-5 with a serial number indicating shipment in late 1967 (C979XXX).
It has a small oddity in that on the yoke the stamping is very light, to the point I cannot see the number 10-. I can barely make out the number 5.
I presume this is not a big deal, but wanted to know run it by the experts here.
I would be very grateful if y'all would inform me this is very rare and makes my little old model 10 worth a gazillion bucks, but I ain't holding my breath.