I think that poster is more likely from 1976 as by April 1977 the 900GTS was introduced and the 860GTS had been on the go since the previous spring, although the 860GT was still sold along side it for a time.
Below are some pics taken of my 860GTS when it was new in Dec 1976 and a few later ones (with the Jota bars) taken in 1978. They might be useful for some of you carrying out restoration. Note that the stripe on the top of the tank was quite narrow. The Conti silencers were supplied from new at my request
Below are some pics taken of my 860GTS when it was new in Dec 1976 and a few later ones (with the Jota bars) taken in 1978. They might be useful for some of you carrying out restoration. Note that the stripe on the top of the tank was quite narrow. The Conti silencers were supplied from new at my request

