By the 1950s though, the model was outdated and outclassed by the new twins and shared only the featherbed frame with its postwar Manx racing cousins, and only sold in small numbers.

These gearboxes proved so good they remained unchanged for the next 30 years,[2] although the external appearance was altered several times, and the gearchange mechanism fully enclosed and thus lubricated.

Close ratios gearboxes were supplied as standard from 1947, and the all alloy engine made a comeback in 1950 .A new Featherbed framewas introduced in 1953 Volume production of the International ended in 1955, although small numbers were built to special order for two or three years after.

[5] Military police from the Provost Company of the Territorial Army's 1st London Division, commanded by Captain Sir Malcolm Campbell, were equipped with the Model 30 in 1940 for fast escort and traffic control in the Coats Mission to evacuate King George VI, Queen Elizabeth and their immediate family in the event of German invasion.

The engine stayed essentially the same, although the lightweight alloy head and cylinder were fitted as standard (previously a no-cost option), and the gearbox was the laydown version (same gears in a revised housing).

The Worlds Best Roadholder" the new featherbed Inter was well behind the specification of the racing Norton Manx – double overhead cams and 8-inch twin leading shoe front brake.

A final facelift for the 1957 and 1958 models was a cosmetic update to the full width alloy hub wheels, chrome plated tank sidepanels, new type Lucas headlamp and tubular exhaust.