I have a number of S&S holders for my 7x17 Wisner which was (apparently) made for Korona holders.

First question: What exactly is the difference between Korona and S&S holders anyway?

I ask because the registration between what I see and what I get is different by a fair bit. WYSIWIG does not apply and its driving me nuts!. Seems like my S&S holders need to go in further into the camera (which would require shaving a fair bit of wood off the back ?) to indeed take exactly what I see on the GG.

Second question: I find the film too loose in the holder on the short side as there is a good 1/4" play either way. This creates uneven film edges. Since I do print those edges, I need to find a way to tightten up and even out this play so that I get even clear edges.

Suggestions anyone?