FG 580

That is the serial number. 4/25/1973. The FG-580 was made from 1971 to 1978.

That is the earliest 5 digit serial number I've seen, the next being another FG-580, made the next day.

The date code would be on one of the inner walls. I'd expect 48.4.??.

All the FG-580's I can find have the 3 tuning forks on the headstock. Yours doesn't. The inlaid torch could very well be factory installed!! Did it always have those tuners? Again, very unusual. I've never seen any like it.

Where are you located?