I'm still helping a friend make space in his garage - one of the things that turned up was a backing plate, which after some flailing around, I believe is an "A1/A2" backing plate - I got to that conclusion by finding the part number stamped on it on the BISON site (the backing plate is visible here:
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. I don't recall anyone mentioning this style, and I don't recall seeing it before - so now I'm curious - what kind of lathe uses this style, and does it have advantages over the L or D styles?