Charcoal burner unit

I'm constructing the charcoal burner / hotplate as a separate unit, so that we can build spiral stairs behind it.  I wanted it to have an arch above the brick hotplate and shelf, so here's what I'm trying.

(Sorry for the photos, I did this part last night and it was dark :)  I bent a piece of cardstock (cut to fit the depth of the unit) until it made a nice arch, then taped it in position and trimmed it for length.  (Note the hot pink theatrical spike tape!  I couldn't find anything else, eh :))  I cut a piece of balsa wood the width of the unit and then taped the cardboard to it.  I marked the line of the arch and cut it out of the balsa wood.

I then taped the cardstock arch to the balsa wood front, and glued the arch in place.  I'll fill in the rest of the front with balsa and then plaster over it, hiding all my awkwardness, I hope, without creating too much more new awkwardness!

The brick hotplate is still removeable, and will stay that way, so that I can install or fix whatever lighting I decide to put inside this thing.

UPDATED 6:16 pm

Here's the charcoal burner unit so far.  I stuccoed the front of the unit with Poly Filla and because I was having problems making it smooth I decided to make a virtue of necessity and make it really textured :)  While it was still pliable I scored in the outlines of the stone arch above it (I also thought of making "stones" and setting them into the plaster, but laziness won out).  The stonework needs a wash of a warmer colour, but then I think's it's about done, except for the wiring and a piece of trim across the front.  Hooray!