Ron
Forgive me if I overlooked the following in your post…But, do you have the threaded aluminum mag plate retainer oriented correctly? The flat side of the retainer (#12) should be facing UP towards the mag plate. I did just reread the last sentence of your post, which seems to indicate the retainer is oriented correctly, just checking though.
Let me know if you need another mag plate, I don’t have the "repair kit" though.
Don