Ah well, no sub, but it sounds fine as it is so no biggie. Thought it might have an amp installed due to dual + battery cables leading from the battery. One goes immediately into the fusible link, the other dives into the passenger fender. I'll investigate that with my flashlight afterwhile.
Did however play with the controls on the rear of the console, seems to change the pattern/effect of the stereo. Small button to the left of the headphone icon changes the reading on the face of the radio from "SINGLE PLAY" to "DUAL PLAY".
"Dual Play" seems to sound okay and after selecting this mode the reading changes from "Dual Play" to "FM1 SHARED" for a few moments and then goes blank.
Dunno if any unicorns were harmed but seems to still sound very good.
t