If you've looked on Morganville, you might have seen that 4704 is listed as a 1960 +4 4 seater, that 4711 is a 1961 +4, but that most of the 47** chassis numbers seem to be 1961.
I didn't think that any 4 seater Supersports were built, except for one built in 1966 (according to Worrall and Turner 'Original Morgan)
Again according to Worrall, from 4650 it should have black toggle switches, and front disc brakes from 4644 (both changes listed as September 1960). TR4 engine was an option from Feb 1961 but not standard until June 1962 (when it was the TR3 engine that became the option)
Malcolm
