love to know more about the adapter plates for M3 mirrors. i made my own as well but not with the brass inserts. i took a picture with my phone of the inside area of the M3 mirror internal bracket and used photoshop to make hard outlines and used tinkercad to make a file. getting the holes just perfectly oriented was a pain because i found that just being even .5 to 1 degree off would cause the glass to be terrible off center.

love your implementation and glad someone finally got their base plates up and ready for sale. i was always bugged to get them out and i never had anymore time to work on them.

put me down for a set of yours as well because i love the brass inserts on them.