I want to use a 150mm lens, but I have the 135mm cam. Instead of changing cams, could I remake the rangefinder focusing scale to work with the longer lens? I was thinking about cutting a piece of tape to cover the old scale, and then taking the camera out and use the GG to figure out the new scale, and write it on the tape. Does this make any sense?

You mean the focus scale on the bed? Yeah sure, that makes sense. A lot of us do it all the time. If you want to get fancy, you can set it up with both scales. It's not hard to do.

I mean the semi-circle focus scale on the top of the Super Graphic with the little red arrow. My Super Graphic doesn't have a focus scale on the bed, but I did change the one on my Anniversary Graphic in the past.

After I posted this message I taped over the scale, and went out in my back yard to do some focusing. I reset the infinty stops so they matched the scale, and then went from there marking various distances. It worked pretty well. I came back inside and did some tests on Polaroid and was having really good luck even at distances as close as 4.5 feet.

The dial/scale on the top of the Super's is a Flash caculator. The surface of the cam that the follower arm,which moves the scale pointer, is not linear; from high point to low point is not a straight line but an arced one. Some minor to major errors may occur.
Try copying the cam on the track,high,and low sides and make the focusing face a straight line to get a more linear responce of the indicator resulting in a more accurate scale. If some distances are too close together then increasing the slope of the face of the cam should result in greater movement of the pointer.
Charles

Hmmm -- that's what I get for not owning a Super.

Well, I've tested it at a range of camera to subject distances at F/5.6, and my new scale seems to be spot on. I'm going to work on fabricating a new cam, but this seems to work in the meantime.