The main adjustment screw adjusts the entire mechanism , that 45 degree is just an infinity stop though, it adjusts nothing. There's another eccentric screw in the mechanism that adjusts the relative travel of the rangefinder over the range.
I had a repair manual for the Polaroid 600SE which uses the same mechanism, and it details the correct procedure. Namely, you adjust the main adjustment screw so that the image is correctly focused at infinity, then, if neccessary, adjust the eccentric screw until the image is adjusted correctly up close.
www.everythingretek.com/PRDLibrary/LIBRARY8/LIBRARY/REPAI...
Page 87 onward, from "Near Distance Tracking Test"
Note that the eccentric screw, in "Figure 5-21. RF/VF near-distance eccentric screw adjustment" is NOT the 45 degree screw that everyone talks about when they talk about near distance adjustment, that screw is just a plain stop.
I got mine to fairly good degree of accuracy, it's off at the near and the far ends by less than is noticeable at about f/5.6 or so.