Best I can do for the East German with the extractor cut under the rail ledge:
Since the East Germans had to have some method of clocking, I scoured the receiver for any type of marking. The barrel has very obvious markings.
Barrel stamps: 25275 and 0D70 over 8
While there is a great amount of pitting at the usual left front area, the witness mark can still be viewed. So, if there were any remnants of numbers, they would at least be somewhat visible. But no stamps at all appear on the left front.
The only other markings are found on the right side, and very lightly stamped.
Receiver number, to the best of my ability to read: [K9] and 27.75
Makes no sense to me at all! But I'll release the deciphering hounds with some pics.