With a serial number from Samick (who made these guitars for Epiphone.
Ie: Yamaha instruments may show Nippon Gakki (Nippon Musical. after CBS, then owner of Fender guitars, worked out a deal with Yamaha Music and Kanda Shokai. Dating from 1985, this unusual shaped guitar was the grand prize in Yamahas then-annual East-West.
I know from the Yamaha archive the FG-160 and FG-160E was only manufactured 1972-74.
The katakana イ is the phonetic representation of 伊. Yamaha must of contracted with them to build some of their guitars.
DATING YOUR GIBSON LES PAUL If at all possible its.