Hi Farmer J, thanks so much for the info - I'll keep an eye out for those!
I recently picked up a 40A socket set, as far as I can tell it's totally complete apart from the 1/4W socket being six-sided instead of 12, and came with a few extras too.
The info in this thread tells me it's likely...
Does anyone happen to have the model numbers for the hex -> square drive and vice versa socket adaptors? Or if you even have spares to sell am definitely interested there too!