The Really Right Stuff base plates for Leica M cameras were announced a while back but I don’t think I have covered them here on the blog:
Really Right Stuff BM240 base plate for Leica M Typ 240 and Typ 246
Really Right Stuff BM240 L-Plate and grip set for Leica M Typ 240 and Typ 246
Really Right Stuff BM240-L set L-plate for Leica M Typ 240 and Typ 246