I went to a small local engineering firm and found one of the guys there was happy to knock me up one to my design for £20
2 foot long but splits in the middle making each part 1ft sq, one has bars the other has mesh, with small vertical tube welded onto each corner, 4 rods with 2 L shaped legs welded to them which enables the L bits to fit into the vertical tubes, but it does have weight and I would not like to lug it about, much better for base/static camp.
An alternative to this would be 4 or 5 U shaped rods in say 1/4" rod with ends sharpened, turn them upside down and drive into ground, spaced about 2 or 3 inches apart, drive points in about 2" and it is stable enough for a kettle or pot no problem, more portable and easy to use.