I'd say the front screw was probably renumbered with the same die. Absent a depot inspection, it is hard to say if it is an armory replacement. I'm not getting a good feeling looking at it, but that is just my opinion.
Sometimes they are added at the wrist, sometimes on the side, sometimes both. They would be in addition to the factory inspecions (Waa37), and they take the form of the first and last letters of the depot and a number: Psn2, Su1, Mz8, etc.
Another "t" block, very cool. I note that yours is not cut for a sight hood, same as my three "t" blocks. Hard to tell on the magazine and floor plate. A field replacement would not have depot marks, but the parts would have single inspection stamps if drawn from early kits, maybe no inspection stamp if from later kits. I say this because I have late war armorers parts from Steyr that are not marked, so it's possible. Is the follower a replacement also?
I took some more photos of the stock and floor plate areas. There are numerous markings on the bottom of the stock, many of which are hard to make out what they are. The magazine follower is unmarked. The metal shows no wear along with basically perfect rebluing, yet the underside of the rear sight ramp is still in the white. What I've always liked about this rifle is the plum colored extractor which contrasts nicely with the blued metal.