1940’s I guess but Nils @Nils Stephenson could throw more light (no pun intended) on the dating. Your posts on 300’s have been very informative Nils, and drawing on your expertise I highlight certain features … … a pump knob that’s fully 25mm in diameter. This arrangement for hood/inner/J-tube/ cap with two cheesehead screws. Photo overlooked, but two-piece vapouriser. Filler cap/air screw. Pricker needle inscribed ‘3’. Jet nipple (poorly) stamped ‘3’. Vapouriser inscription - Optimus Made in Sweden. Valve’s 300cp inscription. The control wheel made of a bakelite thermosetting plastic. This layout for the Optimus 300 designation (dent is ‘patina’). Now for things that set this apart for me as a lamp Looked at head-on, the two Optimus engraved logos are oval … … but viewed from slightly above, as they would be when lighting up, they take on the familiar circular format. Allso a ‘point of view’ thing, the filler cap air screw embossed ‘Optimus’ and ‘Stockholm’ are upside down at eye level … … but are the right way up from a user perspective. Nice touches I think. Aesthetics apart, functional refinement is not neglected, such as the locating pip and dimple to align the inlet for the jet nipple. Visible too on the outside to leave no doubt about the correct orientation. The Optimus came with a partially disintegrated mica globe. I may attempt a restoration … maybe! Burner ceramic is unbranded, but made in France evidently. John
