Looking for further newspaper content, there were BR press releases, quoted in many near-identical newspaper reports, in 1987 and 1994. These appear to be for new or revised product ranges, though it's not explicit in 1994.
In 1987 there was a new range of all-line, regional, and local rovers. The all line rover included Sealink ships to the Isle of Wight - no others were mentioned. The regional rovers had "Freedom of ..." names as well.
In 1994 the all-line and regional rovers are mentioned,. but not the local ones, with nothing about ferries. The Freedom of Scotland travel-pass was featured, and that included Cal-Mac ferries plus P&O to Orkney and Stena ones from Stranraer to NI.
In the 1970s there were a few articles in Scotland that might be triggered by a BR announcement or might not. Most feature the all-line rover and the Freedom of Scotland one, listing some of the extras but perhaps not a complete list. For example, on 1975 and 1976 CalMac ferries included are those on the Clyde, Loch Lomond, and Kyle of Lochalsh to Skye.
In the 1960s there were a number of articles and one BR advert, in 1964. That only mentioned the all-line and Freedom of Scotland tickets, both including Clyde and Loch Lomond steamers. In 1964 you find a "Rail Rover" that covers any one BR region, though again the Freedom of Scotland one has a name too. In 1962 there was a brief mention of a "new 14-day all-line rail-rover ticket", though exactly what was new is unclear.