Just got this, all info is appreciated

[scoutdawg]

I got this a couple days ago in a trade. Its a 1918 Erfurt. It has pitting on almost the entire gun except internally. It cycles and seems to function with no issues. It has 2 mags with it not original I don't think. The pitting has seemed to maybe gotten rid of a couple numbers but the serial on front below the barrel is 3058. Wood grips are in pretty good shape as well. This gun seems to have a different coating on it not blued. I know I have read in a book the late 1918 Erfurt's had a rough coating on them so I do wonder about this. Also would like to know what kind of price I might could get out of it.
Thanks ahead of time