Well for one it's a screw mount camera so you're in the wrong forum, chum 😀
I guess it shows what I know about Leica. 😉
He's learning!😀
Why Flash sync number looks like black not red?
Given the serial number is from a batch of IIIf models (615001-650000) that spanned late 1952 and early 1953 and that this number is on the high range of that batch its safe to say this was born in 1953 as a IIIf. Based on Lager's info, the camera's serial number (<685001) and shutter speed progression (25, 50, 75 instead of the earlier 30, 40, 60) make it the first version of the red dial (second version of the IIIf); too early to have a self timer.
I stand corrected, I missed the IIIF RD without ST serial numbers (615xxx-685xxx). So a RD it is.
What lens is it?