It's tricky. If you automatically get a tachometer when you order a manual transmission, the manual transmission is the "option", whereas the tachometer is bundled. In that case, whoever ordered the car did not check the tachometer box.
There are other cases like in 1967, power disc brakes were part of the GT equipment group option, but was also a stand-alone option. The disc brakes will not show up on the Marti in this case (at least it doesn't on mine).
As far as the trim variation mystery, you can see the number of people that have read the thread, and it would be hard to find a more inquisitive and passionate group on something like this, so to me it appears that we have reached a dead end...for now.