I know you all already know this, but please, please be careful using galvanised steel for building a stove like this.
If you're going to do it, please be sure to burn all the zinc from the steel before you use it in a small tent.
When galvanised steel (either hot-dip OR electroplated) gets hot enough, the zinc will burn off & release some VERY toxic vapors.
Galvanosis is no laughing matter (Ask me how I know) & in a closed environment halfway up a mountain, it can kill you.
Other than that bit of seriousness.......Big thumbs up! Awesome little stove :D