No top final acceptance, serialed on the barrel and receiver in a very un-Gustloff looking font, sideways proofs mainly only seen on depot repairs/builds, and the armorers spare barrel pretty much rule out anything other than a depot build of some sort.
I'd wager that the receiver is roll marked bcd 41 as this is by far the most common receiver seen on depot builds. It's pretty cool and hopefully someone will post up additional pics if they get it. I'd buy it but I'm too hung up on matching originals.