Hi, Just acquired this red top Optimus 500 lantern. Fount has a marking "Optimus 500" and "Made in Sweden", no other markings visible in fount, nor in collar. Runs perfectly after a quick internal clean and external polish. Helox mantle fitted. Any views anybody... what could be the production year for this lantern? Br, Tommi
Hi Tommi, congratulations on finding an Optimus 500. There aren't that many of them around so look after it (it's still on my wish list). There is no accurate way of dating these precisely as they were made over a number of years. Yours is one of the last variation that was made from the start of the 1950s up to 1956. If the top on yours is original (I suspect it comes from a later model) it would put it closer to the 1956 mark.
Thanks Nils! Two pictures about the hood itself only. Those Optimus lamps I've seen so far have a screw mounted top, either one or two screws, this has a different mounting. Furthermore, there's not that much data available regarding this particular model, nor Optimus 550 (... or I need to improve my search skills...). -tommi
This top is the one used on the 350/550/1350/1550 series from 1957 and on. It only changed in the 1980s when they went over to enamel top being held on by a pop rivet. This 500 should have the same style top as used on the 300P. There the red enamel top is held on with a single screw. It is possible that they had some 500 models left over that they wanted to sell and didn't have any of the correct tops left so used the later style. Possible, but I think more likely it was replaced later. What does the inner top look like?
OK, looking at the inner top convinces me that both the inner and outer top are later replacements. The inner top is from a later variation of the 350 etc models. The first ones were in two pieces that were spot welded together.