Riley became part of the Morris-MG-Wolseley Nuffield Organization in 1938. The RM was announced in 1945 and would continue to preserve the Riley character with its technically-advanced chassis and with coach-built body choices of sporting designs. Riley's successful pre-war engine design was carried over and featured hemispherical combustion chambers and twin camshafts operating valves through short pushrods. The four cylinder engines had a cubic centimeter displacement of 2443cc and were fitted with twin SU carburetors. The result was an impressive 100 horsepower and a factory advertised top speed of 100 miles per hour. The engine was coupled to a four-speed manual gearbox and the chassis was fitted with an independent, torsion bar front suspension and live rear axle with semi-elliptic springs. The Riley RM-series cars are often called 'the last of the real Rileys', were among the first redesigned British cars to be introduced after after World War II.
While its early history is unknown, this rare 1951 Riley has been in the long term ownership of a prominent, Detroit area collection where it was restored and maintained to exceptional standards throughout. The desirable drop-head coupe has been the recipient of a recent, professional restoration and today remains in near show quality condition. The Olde English White exterior remains in near new condition with excellent fit and finish seen on all of the body panels. The dark red leather interior was fully restored and today remains like new including the door panels and carpets. The interior wood trim has been restored and the dashboard instruments were rebuilt and appear like new. There is a new black Haartz fabric top with a a matching boot and protective cover which is accented by chrome landau irons. The chrome trim accents were also restored at the time of the restoration and still remain like new. The engine bay and chassis are extremely clean and well detailed.
It is believed that RM-series cars had a total production of only 28,000 vehicles. Most of those were four door sedans and 503 of these were fitted with the desirable drophead coupes bodies like the example shown here. Riley enthusiasts believe that less than fifty of this body style exist today, making this example extremely rare. Given the condition of this Riley, it is also likely that it is one of the finest examples remaining today.