I don't think it is a fake, but it isn't very original. It is a 4-4 (not a 4/4) and with the Coventry Climax engine it dates from before June 1939 (from then on the Standard Special engine was used).

And you are right, Peter. The +4s were not yet around in 1948. Most non-Morgan dealers have no idea what 4/4 or +4 means.

Frank

1967 4/4 1500 Comp.
1935 Super Sports Barrelback