ref no 2072
More info:
The RMB was an enlarged RMA and was launched a year later in 1946. It used the 2.5 L (2443 cc) “Big Four” engine with twin SU carburettors, starting with 90 hp (67 kW) but increasing to 100 hp (75 kW) for 1948 with a 95 mph (153 km/h) top speed. The RMB was replaced by the RMF for 1952.
Reference: wikipedia.org