Well, couldn't find anything in my spare parts to use as a NB backplate so I'm down to 2 options; fabricate one out of bar stock or go without. The widest bar stock I could get locally was 1.5". That should be real close but I would have preferred just a tad wider. I'll give it a try and see if it will work. If not I might be able to do a two-piece backplate...

I really want to use a plate, going without is not optimum.