Retina Automatic III won't reach focus at infinity
I've found that my Retina Automatic III is front-focusing throughout its range, and it won't reach focus at the infinity stop.
The rangefinder calibration and the distance scale correspond: Merging the rangefinder images on a 6-foot-away object causes the distance scale to read 6 feet, but a ground glass on the film rails shows that the lens is actually focused at about 4 feet.
I'm thinking that it's the lens and its helical that need adjusting, but I don't know how to begin to fix that.
Can anyone point me towards instructions for adjusting the lens/helical focusing?
Thanks in advance.