That's a very rare Ruby, and is among the last. Its chassis number indicates it was built in April 1938, and although some saloons were built up to January 1939, Austins were mainly building A7 vans by then since the Big Seven had come along, and the Ruby, to be frank, was a seriously over-weight and underpowered horror, particularly in comparison with contemporary Fords and Morrises.
I've never seen a LHD English-built Seven, though I've seen a few American Austins and Bantams. I think I'm going to keep an eye on this one!