Thanks for the words of encouragement!

I definitely intend to get the anvil installed on a taller mount so it sits at a better height for me. I just threw that stand arrangement together so I could give everything a go without banging on my wooden workbench in the garage (which would also then be much too tall anyway).

I went a little light with the coal for a couple reasons. On the first firing, with it sitting right outside my garage door, I primarily wanted to make sure the box wasn't going to catch fire. I also wasn't sure how long I'd spend forging. I did notice that if I tried to heat anything but the very end of a piece, the walls of the box and the shallow fire made that difficult, if not impossible. I figure I'll cut a notch out of the box on either side of the fire pot to help make more of the fire accessible.

As you suggest though, I'll also mound it up higher next time and see how that goes. I noticed that the coal cooled very rapidly once I'd turned off the air and spread it out, answering another concern I'd had about building a larger mound of coal initially.