I finally got around to making new frames for two QXes that I've had sitting about in the workshop for ages. They are quite old and several of the tenons used in the bridle joints at the corners had snapped. I had been thinking of just remaking the broken parts, but in the end it was just easier to build complete new frames.
Unusually (in my limited experience) they have a small plate crimped across some of the wires at one corner with what I assume to be the manufacturer's name, some sort of registration number and "MADE IN ENGLAND" embossed on it. I can't make out the manufacturer's name though. It could be something like "Wardon". No-one I'd heard of, anyhow. I'll see if I can make anything more out with a magnifying glass tomorrow.
They're also odd in having an obviously rectangular space for the actual QX section -- one pair of sides appears to be 1" wide whilst the other looks to be 2" wide (I'm assuming they're sufficiently old that the measurements would have been imperial).
James