We’ve got a wee conundrum here with a Primus No. 71 stove inside an Optimus 80 tin and to add a little mystery the date code, which can usually be found on the base of Primus stoves, is missing from this one. The logical conclusion is that someone put the wrong stove in the wrong tin by accident, but we think it is rather more complicated than that. For reasons we are not quite sure, both Primus and Optimus produced two very similar looking stoves in the early days and Primus called theirs the No 71 while Optimus called theirs the 80. In 1962 Optimus bought the paraffin division of Primus, but kept the name as Primus Trading . Amongst other things, this meant that they had interchangeable stoves and tins with maybe more of one and less of another. The Primus date stamp would usually have been put on at the time the stove went to market, but since Optimus didn’t use date stamps there was no need. So, an educated guess tells us this Primus/Optimus stove combination dates from around 1970 which fits nicely into the provenance since it was one of a large number of stoves which the Ministry of Defence bought from Optimus in the late 1960’s for use in North Norway by the Royal Marines during their Arctic Warfare Training.