installing the SME V tonearm in the Technics SP10

Lew is correct about the square escutcheon creating the problem, not the platter dimension. I also have a JMW 10.5 arm which would have been difficult to mount because of its off-set mounting base. Unless you swing the spindle to pivot distance template way around to near a 3:00 position for the arm, the square interferes with that mounting base.

Apparently Technics intended only 10 or 12" arms to be installed with this table. And since Tubeperson has the Obsidian plinth, he will be limited to those arms where the mounting template arc falls within the dedicated armboard position.

I have seen an SME V mounted on the obsidian plinth.
Here is an example of an SME IV ...
http://www.theanalogdept.com/k_mccarty1.htm
All he needs to do is make a template. Trace the SME mounting base, outline and hole, onto a piece of cardboard, cut the base out and measure the pivot to spindle of 215.35mm. Then just move the cardboard around on the arm board until it fits and the pivot to spindle is correct and mark up the board for cutting - pretty straightforward really.

Thanks Dover. Yes, it can physically fit. But I wonder how much of the SME overhang adjustment can still be accommodated? Meaning, is this arm at the closest point in the elongated slot so there remains room for standard adjustments with various cartridges?

The SL-1000 (SP-10 mounted in the "obsidian" plinth) was designed for the Technics professional tonearms, with mounting distances of 235mm. I have mounted shorter arms on these decks, with varying degrees of success. Frankly, it just looks odd to me. My advice would be to either hunt up a longer tonearm or mount the SP-10 in a custom plinth.

The platter is 12.5" diameter, most are 12" or less. That, combined with the escutcheon makes many 9" arms hard to mount. I have a VPI 10.5 on my sp10, but it took some twisting.