rjheff: Between November 1984 & January 1985.
kanook: Your first gun is a .38/200 British Service Revolver. Correct caliber is .38 S&W, some were bored out after WWII to accept .38 Special. With that serial number it should date to 1942. Personally I would invest the $50 in a factory letter just to satisfy my own curiosity.
Your second gun is a .455 Mark II Hand Ejector 2nd Model, manufactured between 1915 & 1917. These were manufactured for Canada (14,500) & England (59150).
the .455 wouldn't have been lend lease, as that was a WWII programme to allow the USA to resupply Britain. Your .38/200 may have been lend lease, or purchased by the British military purchasing commission or ordered directly by Canada.