Tim: I don't have enough large US size beer cans to make more of the stoves, so you'll get the internal only 4g version, which is still efficient, just slower. If you send me a bunch of cans (a mix of heine's and fosters) over with the quilt I ordered from you I'll make one to include with your large kettle.
Herman: Yep, I'm really pleased to have hit 60% efficiency. I use british 'methylated spirits' which is around a 90/10 mix of ethanol and methyl alcohol. I'm also building a woodstove similar to yours from a sheet of 0.4mm Ti, it's a nice design. My problem will be that my cookset will be light, but bulky unless I can come up with a way to fold the windshield into the pan. Sure is nice to have that first cuppa within 5 mins of waking though, along with a woodstove to conserve alcohol. The kettle will also work on the woodstove for evening brews. :-)
I'm going through a patent application process for the design of the chimney inside the kettle, so no detailed drawings yet. Once I've got the pat pending I'll be selling a few of these kettles, so you can order one and then emulate it for personal use. If you can work out how the jointing is done. ;-)
Eric: Apologies for the thread hijack. :o)