Hi Doug,
as Raimey already pointed out: it's a post WWII gun. There will be a date code on the barrel flats. As it has the Q1 mark representing outstanding quality (Raimey mentioned this already), the gun was made after 1960. Check this out:
http://de.wikipedia.org/wiki/G%C3%BCtezeichen_%28DDR%29
No English version, unfortunately, so a translation of the most interesting facts:
Q1 (since the early 60s) and S (until 1960) = superior quality over the average level of the world market
1 = good quality on the average level of the world market
2 = sufficient quality; adequate but below world market level
And here's the guy who probably made your gun:
And heres the guy who made your gun:
http://www.calvin.edu/academic/cas/gpa/postersgdr/quality.jpgWording is: Quality you have my word!
(A GDR propaganda poster for the XI. party congress of the GDR's communist party).
Regards
Martin