I would also guess the first is a name, although the characters seem strange sort of like Cyrillic strange, and I'm not sure what to make of that. The second is a Serbian Cross, it's seen carved on a lot of rifles and in some of the heraldry from that region.
A lot of star mags went through GB this spring ranging from about 57 to 106 $, I think the middle was around 70 +/-. If you got a h/g with gas tube as well as the stock that's probably close enough to even. I don't collect trench art but I like it, I agree that and good old-fashioned wear give them character. That should all come together nicely jeep, let us know how it goes.
Edit - I guess it already did come together, let us know how it shoots