German 17cm gun, battery locations and gun numbering system.

[RAFcolumbo]

Hi folks, im in a spot of bother and was wondering if someone could help, i had another post regarding a shell i caught someone throwing away into a dump which i saved without question.

I have since found out thanks to this site that it was fired from a 17cm kanone made by krupp. This particular shell has a plaque that reads GERMAN 7, CALAIS - DOVER, 1944. I would assume that this shell was fired from one of the 2 German gun batterys (that harrassed Dover) located in Calais that were equipped with this particular gun. The 2 batterys were Griz Nez and Sangatte. There were 7 guns divided between the 2 batterys, 4 at one and 3 at the other.

I am assuming that German 7 (written on the plaque) could be the gun number(7 of 7??), were the guns numbered so i could pin point which battery and how common is this size of shell (possible value)???.

I have added some pics which will hopefully help, note the eagle and swasitka stamped on the bottom.

Ive attached some pics