Hi, I was going through some old stuff and found a petromax lantern. I don't know what year it was manufactured, my grandfather purchased it in 80s, there is no number written under the tank, will be glad if provided any information.
Sorry to say, but your image shows nothing but a glass globe for a pressure lamp. In that item which might be a notion of a pressure gauge I would think I see a mismatch in the color which I would suspect to be there. So, without some details no one will be able to give you a detailed answer. Did you search the internet for "Petromax 828" ? Erik