Interesting car! It began life as a 1926 Frazer Nash Boulogne. In 1932 it was fitted with an Anzani from a Horstman and a new fabric body by Abbott of Farnham and was known as the Abbott-Nash. In the mid 30s the engine was replaced by one from a 1927 AC Acedes and in 1939 it was given a lightweight single-seater body and became known as the AC-Nash. In 1946 the chassis was shortened, the body modified and the radiator and engine moved forward. By 1948 it had acquired an entirely new aluminium body built Alexander Engineering, as shown in your picture. Several rebuilds later and a journey to the States and back, it was restored to its original appearance with its chassis back to its original length and now goes by the name of Acedes Nash with the registration number RHO 458. Many owners, four names and, I would guess, at least six different bodies.