"They don't look real to me but that may simply be because I've never seen any just like them before."
Your feeling is quite correct. IMHO, the stock is a replacement ( the wood looks "too new to be true") and the markings are faked. And not even good fakes. M / 71 and 71/84 inspection stamps (Revisionsstempel) always used Germanblack-letter ("Gothic") script. As can be seen on the photo of the knoxform (knocksform? nocksform?) left and right of the "FW" stamp that indicated the monarch/state. And the stamp for the monarch did not appear on the stock at all. So the FW on the butt can only be a fake, regardless of styling. In other words, the faker didn't have a clue what he was doing. And thereby spoilt a good-looking (but not original) stock.
The official marking plan was like this:
Unfortunately, the software doesn't seem to like Windows 8.1. I cannot insert pics anymore, and just get small-sized attachments. Does anyone else have the same problem - and maybe a solution?