I 'think' it was introduced for the '85 model year, and made it to the '86 model year...
The '85 brochure shows it with black suede effect bar tape and the Tange headset, mine had what was left of Benotto white tape and has a Shimano 105 Golden Arrow headset...
You seem to suggest that the 105 headset and Benotto tape are original?! My 1984 Corsa (I bought it new) had a 105 groupset with a Tange
headset and the standard black bar tape.
A pal of mine bought a new Team Corsa in '85* and it did not/has not got a 105 headset, Tange was always fitted by Raleigh to keep costs down, and neither Corsa had the full groupset.
I'll check the brochures though - but I think I've discussed this before on RB
*been dying in his parent's garden shed since the early 90s!
Co-founder of a V-CC section, member South Eastern Road Club and owner of - 2005 Bianchi Reparto Corse (modern), 1985 Raleigh SBDU Pro Super, 1984 Raleigh LU Corsa, 1980 Allin Stan Butler Special, 1978 Ron Cooper, 1975 Bill Philbrook tourer, 2 x very early Roberts (mid/late 1960s), 1966 Raleigh Superbe Roadster, 1964 Allin Stan Butler Special Belgique, 1951 Hobbs of Barbican S/C, 1950 Hobbs of Barbican S/C, 1947 Hetchins Super Special, 1908 Centaur Featherweight. 1988 Specialized Stumpjumper.