Here are the Gun Digest articles by Lee Kennett for proof marks:
22nd Edition Czechoslovakia -1968
23rd Edition Austria Hungary & Austria - 1969
24th Edition France - 1970
25th Edition Spain -1971
26th Edition Italy - 1972
27th Edition Hungary - 1973
28th Edition Russia - 1974
29th Edition Germany -1975
30th Edition Military - 1976
31st Edition England - 1977
32nd Edition Belgium - 1978
33rd Edition India -1979
There was some talk in the articles about a book or collection, but it never seemed to happen. If there were other articles by a different author in Gun Digest, I am not aware of them. Hopefully some one will have more information.
You can usually pick these Gun Digests up on eBay for a few dollars each, plus shipping.
You should be aware these articles, while very good are somewhat dated. He did them mostly in 70's. Some of the eastern European information is limited. None of the articles has any date codes, if I recall correctly. Also the subject of makers marks (trade marks) is never touched.
For Belgian proof marks:
http://www.damascus-barrels.com/bp.htmlYou can get the French and Spanish marks here:
http://www.damascus-barrels.com/More.htmlPete
