Can you do one of the wrist and lower buttstock, under the serial (if distinct enough to photograph), Erfurt is one of the most diverse of the makers, probably due to the enormous numbers made (I am sure the German word for expedient was used regularly at Erfurt). I can't tell if this is a C/B or C/P under the cypher, it could be either, unlike most of the other makers Erfurt cycled through half a dozen or more inspectors at any one time. Even the stable wrist and lower acceptance vary widely within any range (this is unusual for any other maker, even Danzig has stability at the wrist and lower) and the only rational explanation is the diverse mix of weapons Erfurt was working with, rifles (G98 and carbines), P08 and MG08/15, no telling what else, - I think they stopped making bayonets, 98/05's and type II in 1915, but they were probably in other things. Component supply certainly.
Anyway, if you can do clearer pictures of the right side under cypher, a walnut stock usually holds the strike better (unfortunately many in this range are beech, easily the majority, so washed out and indistinct stamps are common, which cuts down on trending stocks- on top of the fact so few take shots of the wrist and lower). Also the wrist and lower, I hate to hazard a guess, C/P is common, so too C/M, - but it could be several others. In these high production years for Erfurt I sometimes question the value in trending acceptance. While it is erratic, its like buying a car, you get stuck in the process so long you hate to leave without the car because all the time invested... maybe I should just stick with RR and BC and cut my losses!