Hi Tom,
Those gearboxes had a lot of apps ,but a lot of them where coupled with villiers engines as in James,f barnet,ect,also fitted in early go carts +the close ratio internals fit the early greaves challengers used for scrambling in the mid 50s to mid 60s,but the clutch looks a bit light for competition use, most likely a cart!......sit tight until a villiers expert reads your thread and you will get the right details off the no s..............stay lucky