there was the 2.5 pi Mk1 that came out about 1969 and had the same shape as the older 2000 models, the MK11 was 9 inches longer (and heavier) with slightly different front and rear.Same motor. Above Photos #2 and #3 are the Mk1 models and #1 and #6 are the Mk11. The Mark 1 went like stink and also came in Hot Mustard and was a head turner in it's day. It had the same motor as the triumph TR5.