This is a throttle control cable for AJS Stormer 250 370 410 1968-74 with Mikuni carb. I'm not sure where it was made, it looks to be somewhat universal with a midway adjuster and the stepped ends, it will probably work for a number of vintage motocross applications for Mikuni carb. The little tag says OTC Mikuni throttle cable.

My name is Tony Schanz, I formerly ran DomiRacer Distributors in Cincinnati, Ohio buying and selling vintage English, Italian, & German motorcycle parts, tools, accessories & memorabilia. DomiRacer closed 6/11/2013, but I still deal in parts, motorbikes, decals, advertising, photos, posters, & more. Please add my store, The Real DomiRacer, to your favorite sellers and watch for other rarities in my future eBay listings.