Hi folks! Here's an interesting stove I was lucky to pick up recently. I have not done a thing to it yet, but it's near the top of the fettle pile! Though filthy, it's unmolested and I expect this one will clean up very well. My other Optimus 11 is a bit battered, so I bought this one from Sweden to replace it, figuring I'd sell off the rougher stove. While waiting for it to arrive and fawning over the auction pictures, I noticed some very odd characteristics, leading me to think this stove is a bit more special than I'd anticipated. My suspicions were confirmed when it arrived. Before we dive into it, the earliest appearance of the Optimus 11 I can find is in this 1939 catalogue. from the CCS reference library. So it was produced from approximately the late 1930's until the introduction of the Optimus 111 in about 1952. Aside from some minor variations, there seem to be two distinct generations of the Optimus 11, right? The older ones with the patent on the lid, like this one. And the newer ones with the Optimus globe logo, like my slightly battered one: I propose that there's a third distinct generation of the Optimus 11, this transitional one. I believe the one featured in this post is a very late Optimus 11, among the very last of them produced, and somewhat of a missing link between the Optimus 11 and the subsequent 111. I also propose that this was the first appearance of the familiar Optimus 111 style case, still seen today with the Hiker +. Take a close look at the case. See the rounded lips of the case halves? Similar to a 111, no? On the older model, the edges are not rolled, and are of a thicker gauge steel. Now compare the front of the cases, including the clasps. See how the stamped louvers are gone, and how it uses an 8R style clasp? This style of clasp can also be seen on the earliest 111's, like here, here, and here, and also on my early transitional Optimus 111. You can read more about that stove here. One of my favorite parts of the second generation Optimus 11's is the globe logo. It's much nicer than the embossed 111 cases, and it's tough to capture it in a picture, but the globe stamping is actually convex! The downside of that fancy logo is that they don't stack well. See how it's domed and raised off of the case? On the featured transitional Optimus 11, the globe logo is stamped flat on the case, like on the embossed 111's. Now lets peak around the back of the case at the hinges. The older 11's hinges integrate the handle and are fully outside of the case. The transitional 11 introduces new hinges, which can be seen on the early 111's too, like on Motoshi's example here. Another shared feature is the access hole for the regulator. In my slightly earlier 11, a wide slot is cut. But in the later 11, the familiar round regulator hole seen on the 111 has been introduced. In this picture it is of smaller diameter than my transitional early Optimus 111. You can see here that it is smaller than the early Optimus 111 as well. The featured 11's case is very similar to the early 111's. The most significant differences I've noticed are the model number embossing on the case, and the spirit cup retainer. Model embossing on Motoshi's early 111. Spirit cup retainer on Motoshi's early 111. Now lets discuss the wrench for a second. Mine was bought without a wrench, but I found a correct one on a New Zealand camping supply site for a modest sum. Earlier 11's used a different wrench, as seen here in the middle, but I believe these double open-ended wrenches were introduced late in the Optimus 11 production, and used until the early transitional Optimus 111's. You can see examples of this wrench with later Optimus 11's here, and here, as well as on both of my Optimus 11's. You can see examples of this wrench with early Optimus 111's here, here, and here. You can see examples of this wrench with early transitional Optimus 111's here, here, and here. Another odd feature of this stove is the pump knob. See how it's significantly smaller than both my other 11, and a 111's? Maybe it's shared with a small contemporary Optimus stove? I have no idea. The pump shaft is also brass instead of the earlier stove's steel shaft, and there are minor variations in the pump leather retaining nut. With all that squared away, the only other similar stove I've been able to find is seen here in Motoshi's collection. It's also an 11 with rounded case lips, the 8R style clasp, and the flat Optimus logo. Curiously, his also has the small pump knob. Tangentially, another odd but relevant stove can be seen here, here, here, and here in Morris's collection. His must have been among the very earliest of the 111's, as it used the same 11 embossed case, but modified for the early 111 burner. Well, that was all terribly pedantic. Thanks for suffering through this post, and I hope that this has contributed something to the evolution of the 111! I feel very lucky to have both of these in my little collection, and this new stove is high up on the fettle pile. I'll make sure to post pictures of the results! Happy stoving!