CRS is a terrible disease. I find my case is progressing with every passing birthday. I thought I had two Primus No. 2 stoves. I don't. I have one Primus (just posted in another post) and an Optimus No.2. The Optimus has no date code or any other marking except the name and the 47 language patent info on the top of the tank. Can anyone make an educated guess at the age/date of the Optimus? BTW, looking for a trivet for the Primus if anyone has a spare. Cast iron or sheet metal, either would do.