Here are some pictures of Valley Trash's Close Call...
Looked on Fairbanks Craigslist, searched coal under for sale/wanted, found wood/coal stove in Salcha, not sure if it is worth owning. http://fairbanks.craigslist.org/for/2092019161.html
This link is broken, either the page no longer exists or there is some other issue like a typo.
To burn coal you need grates, to get that underfire air.
I see from you picture in Using Bituminous Cloal you are using a barbique grill for grates, I would have thought it would just turn red and sag.
If you are going to weld up a box, I think the heat will flex your mild steel door and cause air control problems, just to start listing problems with that Idea, although Romax may have a heat shield you could copy.
Found this add searching "coal" on Alaskaslist.com under general http://alaskaslist.com/1/posts/9_Genera ... Stove.html
The cold has come to Cantwell, -20.
Just thought I would add a link to parts for your Vigulant 1C and the Vigilant II I sent ad for, dosen't look like a few parts will interchange to convert yours to a Vigilant II. http://www.discountstove.com/partsvcwbf ... m#Vigilant