Built this yesterday afternoon:
cut the 20 ga stainless to size, file the edges thoroughly (~$50 Cdn for a 55x22" piece)
BFH the edge while clamped to a solid piece of wood
drill some holes for the hinges and for the cable to attach
thread the 1/8" aircraft cable through the holes in the gate ($30 for 100 ft)
bolt on the hinges (had them already)
install some self-threading screws (had them too)
polish with emery paper if you want
done!
We have a metal windscreen that we will use to protect the wiring while we use the stove.
I still plan to add a small piece of angle underneath, and/or a third hinge. Leaning towards just adding the angle.
You will notice a bent wire clip at the top that holds it closed that I made with two sets of pliers. To stop the whole thing from rattling while driving, we have a blanket sandwiched in between, but you could easily add some dynamat underneath.