According to this WIKI, I figured that the MIJ Epis meant for export didn't have the 'open book' headstock, so that might explain also the 3 hole TRC, but the serial number does not really work:
- it should be YMMPPP format and mine is YYMMPPPP
- it seems that until 97, Terada was only manufacturing semi-acoustic Epis. Serial numbers for solid bodies seems to start from 98 onwards:
In 1983, Epiphone export production moved from Japan to Korea [7] and In 1987, Yamano Gakki obtained the Epiphone Japan dealership and produced a limited range of Epiphone Japan semi acoustic models in cooperation with Gibson. The Terada guitar factory in Japan was used to make the Yamano Gakki Epiphone Japan guitars. After Gibson and Yamano Gakki ended Orville production in 1998, Gibson and Yamano Gakki produced an expanded Epiphone Japan model range including solid body as well as semi acoustic models.
Still confused. Would it be correct to say thet it is either an unrecorded LP Special from Terada 97, or a Korean LPS with unidentified J-serial number?