As a new member on Optimus stove nr 2 (only a week after nr 1!) something new came up that I've not seen anywhere on "google", including the forums..... The burner cap on my Optimus silent burner is secured with two small screws! (See photos). (The cap is marked "Optimus", though it's not easy to make out on the pics). Anybody seen that before? Does it help date the stove?? The sticker (fuel types) with the silent burner makes me believe it's a 111T ...but with the more "classic" filler-cap valve. The pump is o-ring, not leather. Just thought I'd hear if screws on the burner cap er anything "special"...couldn't see them on the ad, and I only paid 33 dollars (equivalent) for it to use it....so it's not major important. I've got (hopeful) bids in on a 8R and an 8 too.....again to use, not to decorate with. Regards to all, in hope of knowledgeable feedback. Martin.