1920 DWM question

[saxman]

I believe I have solved my Luger. While cleaning it tonight after Sunday's shoot, I discovered the imprint of a unit mark on the inside of the front strap. On the outside, it's been neatly sanded off without a trace. The mark can't be read, but that's not important. The facts that the cannon and frame have different suffixes but match in old rust blue, the original sideplate was marked on the bottom in the commercial style, and it has the Eagle/AYA4 proofs on the right side, indicating a rework, had me puzzled and there didn't seem to be an answer for it. Now that I know about the old unit mark, it comes together. I now believe it was assembled from several guns after WWI, refinished and sold as a commercial, but in Germany, not for export, as it doesn't have Germany on it. All this must have happened in the '20s because of the old rust blue. How it got over here is anybody's guess, but I would imagine it had something to do with a G.I. So, how do you like my theory?