There was an ET model that appeared in the mid year 1983 catalog.
They called it a "Super Edition Limited Model".
The catalog lists a TST100-ET, but it is not the equivalent of a TST100 from 1982, and has lower specs.
TST100-ET / SUPER EDITION LIMITED MODEL / ¥100,000
Emotional sound machine finally appeared. It is a popular guitar with Tokai's original tremolo unit E.T. mounted. Perfect tuning for thrilling, attacking, powerful and exciting sound. The ever-changing tonal color ushers in a new sound vibration.