Hi, I am the current custodian of this fine Primus No.50, which I received two days ago (Thanks to Nick and Ross). https://classiccampstoves.com/threads/11155 This is the steel-tank model of the Primus 50-series. The tank would originally have been dull Nickel-plated, but some of this has been lost. These stoves and are relatively uncommon, probably as a result of tank corrosion during their lifetime. The Primus No.50 is fitted with a roarer burner. This particular example dates from 1939, as you can see from the photo of the date code, which unusually for a Primus stove is located on the top of the tank, under a press-fit collar, which surrounds the upstand socket. Here are some photos: The stove performs powerfully and easily passed the Kerophile "Tea Test" after I fettled it. There is a little yellow in the flame, but this is to be expected as this is the first tank of fuel for a long time and I did have to clear some rust out of the tank. Best Regards, Kerophile.