Coming a bit late to the party - travel and family stuff...
David sent me an article from Pottery Gazette in 1970 announcing the launch of the Ravenhead Vista range. It came in two colours, "a rich turquoise" and "amber-gold". (I think this was the first time Ravenhead had used coloured glass.) The tumblers came in three shapes, each in three sizes, Angel (cylindrical with a hobnail base), Venice (curved conical with heavy base) and Nevada (textured cylindrical), and there were also bowls, dishes, ashtrays and a water set.
The range was designed by Alexander Hardie Williamson, and the glasses were sold in special packs designed by consultant designer David Harris: “echoing the Vista name, tumblers are arranged in sets of six to give a panoramic appearance, with a coloured reproduction of Niagara Falls at night on the back.”
There are pictures of Angel and Venice in the Design Council Slide Collection (http://vads.ahds.ac.uk/
) - unfortunately, Niagara Falls aren't visible - too tacky for the Design Council, perhaps?