I carried an English Cyclo spoke wrench that resembles yours in the watch pocket of every pair of jeans I owned for many years. It was raw steel, polished by my pants and oiled by my fingers. It fit spoke nipples well and trued many, many wheels before I lost it, probably to a washing machine, years ago. I couldn't find a replacement until I was given two new-old-stock ones last year at Trexlertown by a kind vendor. Before then, I had (still have) a Park green one. A fine tool, but soulless. I never looked twice at all the cheesy Cyclo knock-offs, although I had to use them from time to time.

I've built several wheels recently using the Cyclo. The feel against my thumb and forefinger of the levers is as evocative as a smell from childhood.