Andy
Spec does not wholly add up.
1960 car will have discs - Morgans were the second manufacturer to fit discs after Jag, mid 50's on I think.
I always thought that the TR3 was the first UK production car to have discs. That was in 1956. I think that Morgan offered discs as an option in 1959 and they became standard in 1960 (on the +4 anyway, can't find the info on the 4/4).
Jag certainly fitted discs before Triumph, but maybe not on production cars, Citroen were also earlier but not UK?
Malcolm