Yes, you are correct, it is a soldered zinc-plated can and no signs of rust or having been opened. The metal does have a bit of white powder on it, understand its just zinc-oxide, rather common with these cans from what I'm told. I've only owned it for about 10-12 years, kept inside in conditioned space, but I have no idea how previous owner(s) kept it. I can only assume that the contents are still in the condition when they were placed there.
I'm still trying to verify if all of these cans from that era contained 300 rounds, and did they all come with original
Russian
stripper clips? I'm still tossing it around to open it up, see what's inside, keep a few packs of ammo for myself & sell the rest. But then again, I haven't fired any of my Mosins in about 8-10 years, so I may just need to sell it all. Decisions, decisions.....