I've sent you some better photos of the 515 than that one Jeff (I shouldn't have used flash there, the dial doesn't like it much).
I forgot to send on the serial numbers with the photos, so I'll send those on too now - remember, everyone, we're trying to find the lowest and highest serial numbers for each model that we can to help us narrow down date ranges. This will help with dating all the other models too, so hopefully something to benefit everyone!
Will take some more of it and the 573 F this week.