First, welcome to the forum
67Lemanster, welcome. You can learn a bunch at this place. Thank you for your first post, and even more for a good question... One that I think I can at least partially answer.....
Bavarians... You may have noticed my several posts on what I received. Why did I bid on the six?? Each from a different political entity. Primarily for the history. I would not consider shooting any of them. Nor would I consider changing out any of the parts. Their condition, as received from the CMP is as much a part of their history as their original condition WAS. Having done a little research on Bavarians, I liked the different marks and treatments the Germans did on these weapons. In fact, one of my Bavarians had the receiver ground down much like yours. But still identifiable as "M 1 Carbine" It's just what the Germans did to them. Obviouly some moreso than others. It's their history now.
So I guess the question is, did you buy the rifle for the history, or for shooting? Or for both? If history, then what you have is certainly historical in the fact that as it is right now, its exactly as the CMP shipped it to you.
To me, as you describe the rifle, the matching numbers are really something to hope for in a Bavarian. They are NOT that common, I'm thinking. But I can also tell you that the CMP is, as you stated, very interested in satisfying it's customers. You can return your rifle for another "luck of the draw", but you very likely would NOT get one with the numbers matching. It would be a "crap shoot". A matching numbered Bavarian is most likely to be "as used by the Germans."
If you read my earlier threads on the Bavarians, you will note that in the last two, I allude to another "Bonus Bavarian" so to speak. It is a matching numbered rifle, but with an Erma barrel. When the G.I. barrels wore out, they replaced them with some fine high quality barrels, mfg by Erma on surplus G.I. machinery. To ME, this does not detract from the rifle's history, but adds to it. As it certifies it as Bavarian, and is not something faked.
As soon as I return from Louisville, I plan on posting this "Vol VII" of the Bavarians. I think you might find it interesting, and will have a surprise or two.
Excuse the rambling !! And again, Welcome Sir!!
Ronnie