I would be interested in Contax G Mount with AF, but think this will not happen. The best mount for Ricoh might be M-mount (My vote) . It’s open, no AF to implement, size fits well to the body and they produced some (2?) M-Mount lenses in the past.
If we dream a little bit: What do you think about the option to adapt to one of the unreleased mirrorless lens mounts of the big two?
If we dream a little bit: What do you think about the option to adapt to one of the unreleased mirrorless lens mounts of the big two?