I don't feel there is any question in terms of authenticity; I have seen some legit German rifles that looked as if the most anal armorer in the world had handled them and some that look like they were stamped in the middle of the night by a private in a drunken rage. Prime example is my BCD G43; it's also of 1944 production and exhibits some rather sloppy workmanship in terms of machining, proofing and other stamping. And, when one considers that the workforce was less than motivated to strive for quality, sloppy markings are possible. Another example are the Brits, whose enfields take a noticeable dip in stamping quality as the war goes on. Anyone who has handled many enfields and seen where numbers have been struck out FOUR different times on a nose cap (!) or a rear sight will know that they can be just as nit-picky as the German armorers but sometimes, as the war went on, there just was not time to do so.

In terms of the numbers not matching... That too is also possible; in the turmoil of post Nazi Germanyicon and Austriaicon, I can imagine more than one rifle was assembled from spares and taken home. In terms of rarity... Dual maker marked rifles are an oddity, and the Rune is an additional boost of value. Unfortunately, in poor condition and without matching numbers, it wouldn't command as much as it could in better shape (obviously) and so I would put it in the very uncommon to rare category, and would expect one in great shape with matching numbers to go for maybe 800 or so on gunbroker, maybe more. One in lesser shape... hard to say; it all depends on whose looking when you posted it. For me, I would love it, but probably would try to hold out for one in better shape, matching numbers, etc. I would keep it if I were you; its an odd bird and despite condition, a hard to find piece.