Thanks for the additional photos Alan.
8.82 is the gauge marking or the distance between the barrel lands.
Lands are the raised portion between groves. Groves are the lowered portion in between lands.
The distance between the groves is 9mm, the distance between the lands is 8.82mm.
A guns stock is normally numbered to the gun but like magazines the chaos of war usually makes this marriage lasting unlikely.
Like Mac Cat says the gun does appear to be buffed in places and is likely at least partially re-blued .
Maybe just cold blue touch ups ... hard to say without literally seeing the gun.
The lack of a 'suffix' to your serial number means your Arty was amongst the 1st 10,000 made.
I have a 1914 Erfurt Artillery as well, 6051 w/no suffix.
Bottom line Alan is your gun is beautiful and I would be proud to own it as I'm sure you are.
