I'll post some images of the rifle a bit later. It came with an inspection record and I spent some time doing my best to translate it and notating it with some info I've picked up here and elsewhere. Still have some bits I'm not sure about so I wanted to see if anyone here might be able to help with the outstanding questions. The text in those areas are in blue bold format with some questions in the light yellow boxes.
Any insight would be helpful. Hoping this may help others looking at these logs in future.
(https://i.ibb.co/HH5NN10/Front2.jpg)
(https://i.ibb.co/swMsGYx/Back2.jpg)
(https://i.ibb.co/p0xWQbx/Inspector-Mark.jpg)
Nominally they all have a 7.62mm bore but the bore was probably measured with a muzzle erosion gauge during inspection at 7.64mm (.3007”). That is likely within specifications for new, and certainly indicates very little to no wear.
Yes, Tectyl 502C is a European long term petroleum-based preservative functionally similar to the American name brand Cosmoline.
I believe TK is Technical Controller (inspector) and the 510 is probably assigned to an individual inspector or perhaps a team, as you have already mentioned.