@mrclubike I've talked extensively with MG cycles. My calipers are threaded ears, and the caliper ears go inboard the fork ears on the front of the fork legs.
MG offers two F09 calipers (right and left behind the fork), in two threading options (BMW threaded, and guzzi non threaded). They say the caliper castings are otherwise the same.
Interestingly, I found those part numbers via fiche as well, and 34 11 1 454 185 is for the wrong "side" since my caliper mounts in front of the fork leg. I thought that perhaps the right side behind fork would fit, and it would mount up, but its offset doesn't match the rotor. One of the pictures in my album shows the right side caliper and mine aligned at the mounting ears. The rotor slot is off by a centimeter or more.
It's possible I have the later caliper, which would be something to try, but I think my next move after the primary cylinder rebuild is new pistons, if necessary.