I may have one that is both original and NOS, OldPX10. Zinc-plated, 44mm long x 7mm diameter, 13mm head diameter with a single key spline and a 12mm nut with a 2.5x12mm round shoulder. I paid over ten bucks for it in a fierce eBay auction--five bidders running the price up from 99 cents to my winning bid in the last 40 seconds--only to discover it was just a hair too fat for my 75 Gitane restoration project.