After years of messing about with makeshift methods of tightening small nut sizes, the increasing complexity of my models, declining digit dexterity and the need to do multiple fit and disassembly pointed to a need for hex sockets from 3mm to 10BA bolt sizes.
Not finding them available on the net required them to be made. Being blessed with years of collected bits that will 'come in useful ', the answer lay in the accumulated Allen keys that seem to have bred over time and the shanks of damaged pin and other punches.
After annealing the punch, the pointy end is turned or ground square to the shank with a size just larger than the hex head in question . The punch is then drilled with a hole diameter equal to the distance across the flats of the hex nut.
Selecting an Allen key with the closest size to the nut in question (slightly smaller is better than too big) the end of the key is roughly ground to provide a lead into the hole.
Heating the end of the punch to cherry red the key can be started into the hole and hammered in. With subsequent cycles, usually two or three, the hex hole is formed deep enough to just allow the nut or bolt head to sit flush. A bit of wiggling when the punch is at red heat will allow a smaller key to make a larger hole.
Naturally these sockets may be made from silver steel stock. Each socket has its size stamped at the blunt end and the working end hardened and tempered.
The sizes shown in the picture are sizes from 3mm to small head 8BA,
my 10BA has gone walkabout hence the bait box now holds the sockets.
The process takes less time to complete than to write about.