[QUOTE=Mark G MacKenzie]
It has been modified for 5 x 7 which I will keep but I also wish to make backs for full plate and 4 x 5.

All you have to do is wait until the camera gets to you. Take the back off and dupelicate the way it fits to the camera. Then buy a 4x5 back and mount it exactly like the 5x7 back. Use small nails cut down for the retaining pins. You can use a good grade of 1/4 in. ply wood cut to the exact size of the 5x7 back then cut another piece 1/4 inch smaller all around and glue it to the center of the larger piece. Cut out the center to fit the 4x5 back you buy,
stain it or paint it, put in the pins and your done. An easy way to locate the retaining pins is to simply tape the back on the camera and mark the locations through the spring clips. Top and Bottom. Be sure to put in extra pins so the back can be used vertical or horizontal. I have also used 1/4 inch Masonite to build reducing camera backs. Baltic Birch is nice, but is not often available for me out here in the sticks.

Very easy to do!