Thanks! I'm comparing your photo of the M21 to what I have. I guess it looks like I don't have the cables from AV?
This is my left connector (M21)
https://drive.google.com/open?id=0B72qQeKA6G0IVGo0R1l1b3JfUG83YU4zbDI2WnNzWmVRRXlV
And this is the one on the right (assuming this is B3?)...