I hopefully can answer some of your questions. I bought a Micro Seiki DQ-30(?) TT because of the MA-707 tonearm that was mounted on it. Subsequently I acquired an MA-505 tonearm and no longer needed the MA-707 (which in the end could not easily be removed from the table anyway). Both the MA-707 and CF-1 had the arm tube markings and came with the additional sliding weight. If the weight is not included the arm is incomplete. To me these arms looked identical and the only difference was that the CF-1 was made out of carbon fiber. Unlike the MA-505, the MA-707/CF-1 does not allow for repeatable/on the fly VTA adjustment.
Micro Seiki MA707 vs CF-1
I see photos of these two tonearms, and they appear to be identical. In both cases the arm tube can be black in color, which I assume means that it is made of carbon fiber, and has markings at regular intervals from pivot to stylus. However, sometimes the armtube has a sliding weight on it, sometimes not. I understand from my reading on the web that the graduations on the arm tube along with the sliding weight are used to adjust tonearm effective mass. So, two questions, really: What are differences between the two arms? If I see an arm tube that is black and has the graduated markings on it but no sliding weight, is it likely that the arm is incomplete? And BTW, does the MA707 or the CF-1 offer any kind of repeatable VTA adjustment, on the fly or otherwise? Thanks.