No, not an RC, and no, wasn't German done...you might find an odd mismatched part if done by a Waffenmeister in the field, but depot level repairs were typically, well, German. They would re-number the parts properly and keep the rifle matching. They had plenty of un numbered spare parts of all types, and would number accordingly, and then the depot would mark the wood usually on the pistol grip, so you could tell who did the re-work.
This was either put together post war from parts, or something along those lines...the no import mark doesn't mean a lot, rifles didn't require import marks until after the GCA of 1968, so it could just be an earlier import. It could be a parts rifle put together by an importer from parts from damaged rifles...who knows...but definitely didn't get captured from the Germans like this.
Still way better than an RC in my book...