I find it absurd that there isn't consensus on this rifle, the rifle is bad, the bolt so obviously it's almost (IS) laughable... there are several other irregularities at play but the FACT that this range was at the a$$* end of SDP Steyr parts (e/623) and the first real reliance on SDP-Radom parts (e/77) (a&b block of 42 can be tricky and there is overlap, especially the whole a-block and early b-block) leaves some doubt of where the good and bad part ways...
It should be noted that although parts supply was in flux, assembly and conformity was stable and done at SDP-Steyr, no KL labor at this point, so deviation on this scale is next to impossible
*** i suspect some refinishing is at play too, there should be an e/77 on the RR, by the early a-block this was near universal, and either way the WaA623 would be present if not, -all SDP production should have a clear RR WaA and I have never seen an exception until Astrawerke supplied a few in the 42 d-block (in all cases there should be a RR waffenamt.