It probably is Boxer primed. You may need to have it annealed before reloading as old brass can get a bit brittle in the neck. However, you might also get away with it. Is the brass clean or in need of a clean up? You can use a mix of vinegar, hot water, washing powder and a few other household ingredients that I'll need to look up, but it does a great job of getting back to clean metal. Once you've fired it, or pulled the bullets, that is.

I can only guess at why it doesn't have NPv such as, they simply overlooked this rifle - or rifles being exported directly at that time did not need it, (because they'd be proofed in the country exported to). However those are only guesses and the real answer might be different. They weren't, for instance, manufactured under licence in the UK.

With a bit of luck someone else might have an explanation.