Turnbuckles

I have a wall mounted cooker I'd be happy to move along, but it may be too big for a Contessa, but I don't know where you intend to mount it.  If you're curious, look up an Optimus 45 stove on Youtube - there are a few clips of them on there.  Mine comes with the original cast aluminum parts for a gimballed mount in a boat.  Also, if you do go to Youtube and see the different styles you'll know what I mean when I say that mine has the "silent" style of flame spreader.  Besides the size of the thing, it may be a bit exciting to light in the confines of a Co., though I've only lit it once myself just to see if it would go, and it did.  I think that's the first and only time it's been lit - it still had the "inspected by" sticker on the burner when I got it.  I can tell you that Hal and Margaret Roth had one in Whisper, but it was a rather larger boat.

You might consider one of the small cookers meant for mountaineers - some of them came in a hanging mount meant for suspending from a rock face or inside a snow cave (seriously, you can cook in a snow cave).  If you want to go that route, go to the MEC website, to the gear swap, and ask for a hangable cooker - you might find one used.