Different stock models were fit with telescopic shocks at different times. Plus 8s were the first from February 1991. However, the hoop-bracket changed, which is why there should be two lengths of shock offered, depedning on when you car was made in the early years.
Overseas variants had them fit years earlier depending on the dealer. Set up and angling were different.
gmg
P.S. I heard TOK had shocks fit back in 1962, in a similar fashion to the Rutherford conversion, save the upper post was rear of the axle, rather than forward of it. An arguably better angling. I can ask RSB if anyone is interested.
P.P.S. David (Rutherford) also offered a later version that he felt was smarter. The bottom post was lower, allowing for more shock travel. Morgan trads have to make the most of a VERY limited area of up-and-down movement (called "travel").