The bolt pattern for a Graham is different from that of a Triplanar. If I recall, the standard Graham mount has 4 holes on a 2.2" bolt circle. Don't anyone get out your drills based on this ... I'm going from memory.
I've never seen the Graham which mounts to an SME pattern, but I would have to guess that the 4 holes are located where they would be for an SME base plate in a rectangular pattern which is outside the oval SME-shaped hole.
Bob Graham after all, came out with the SME mount to make it easy for SME owners to swap to a Graham. Bob is nobody's fool and I think it was brilliant on his part to select the SME V for his target market, as it was owned by quite a few audiophiles in the mid-eighties (when he introduced the Series 1).
Back on topic however ... you own a turntable which has quite lofty sonic goals. I can't understand why you would be selecting a replacement tonearm based on compatibility with an existing armboard.
Something is missing from this story.
One would expect your tonearm search to center on your sonic tastes, and only then to try to figure out how to make the mechanics of it all work.
It can't be that Clearaudio will not sell you a blank armboard, is it? If this is the case, then there are clearly solutions to this problem.
Thom @ Galibier