Sexton is an attempt to provide to the Commonwealth Countries a motorized version of the 25-pdr meeting their needs and specifications. One used the chassis of the Canadian cruiser tank RAM II (based on M3 Lee) to realize a model similar to American M7 Priest. The prototype was completed on August 28, 1942 and Sexton accepted its homologation immediately and an order of 84 specimens had immediately placed. Contrary to the American model Sexton did not have a ring-station for anti-aircraft machine-gun of 12.7 mm (.50cal) M2HB. The latter was replaced by Bren .303cal (7.7 mm) anti-aircraft (seldom used). Another point of divergence, the driver took seat on the right tank and either on the left.