I have both a graflex rb super 3 1/4" x 4 1/4" and a graflex rb series b 4" x 5". I was wondering if there is a way to modify the 3 1/4" to accept the 4 x 5 back? I realize that the image on the negative would be cropped, but it would be much nicer for me to have just the 4" x 5" to deal with in terms of my local shop that develops the negatives for me (does not like to do the 3 1/4" and the carrier size of my scanner; (epson V700 with only 4 x 5 carrier size), and the better variety of emulsions available in 4 x 5. I would imagine that the ground glass would also have to be masked off as well? Any insight on this would be great and much appreciated!