As I mentioned in this thread http://forums.thedentedhelmet.com/showthread.php?t=6107 I have started working on my aluminum backplate, which will mate up with my resized collar armor.
I customized my template, starting with a couple of the templates available on this site, adding in some details from the MOM & ASW reference photos. I then fit the size of the armor to my back, and finnaly tweeked it to match up with my collar armor.
Using the template I cut a 24"x24" piece of .090 aluminum to the pattern with a metal blade in my jig saw. I then used a bench grinder and my dremel to clean up the edges.
Next steps are to shape the armor to my back.