Yamaha FG -512
by Ray W Roldan
(sunland, ca.)
The serial no. looks like 70615078 but i could be wrong about the "1"!
ANSWER
Hi, Ray--
Yamaha serial numbers are recycled every ten years.
Your guitar was made on June 15th, 1987 or 1997
Production Number: 78
The FG 512 model is not priced specifically in the Blue Book. Here is the general information provided about the FG series:
These guitars never sold for too much money, and because of this arenīt very collectible today. Most of these gutiars were played on because they may have been a guitarists first instrument. Most guitars are worth between $50-$250 depending on the condition and features.
Here is a link to a discussion about the guitar including the prices that some people have paid for it:
Harmony Central
Hope this gives you some idea.
Lynne