I have 2 top RF crown 4x5's with identical problems. Both have 135mm Optar's and #6 cams in the rangefinder. With the focusing rails drawn in as far as possible, neither rangefinder will converge the images on a subject about 1 mile away. Both come close, but not completely. I understand from reading these threads that I must do this, lock the rails, them move the front standard until focus is achieved on the GG before I can properly set the infinity stops. Is there some other adjustments to the top RF (other than the cams) that I could explore?

My Pm repair manual talks about a Special Cam Gage (T-34700-G) that is 0.437" tall (+/- .0002)

this allows the rangefinder to be at the proper position when setting infinity stops. Not only does it move the mirror into correct position but puts the balls and spacers in the right place too.

No I have never seen one of these or heard of one *******. You could try to find Fred Lustig (last known phone: 775 826 3056) or Midwest photo exchange: http://www.mpex.com

They aquired all of the remainin stock from WD Serivce a few years back.