He gained Aberdeenshire West (roughly equivalent to the modern Kincardine & Deeside seat) for the Liberal Party.
Wikipedia says of him:
During the 1966 general election campaign one of Davidson's main policy points was the establishment of a development authority for the North East of Scotland (on the lines of the Highlands and Islands Development Board) and he was a strong advocate on behalf of small farmers and of improving communications in remote areas like the Highlands by improving road links to the major cities. He also campaigned for better air and sea links with Scandinavia.
Davidson was Liberal spokesman on foreign affairs and defence issues in Parliament, a particularly important brief given the ongoing war in Vietnam and the arguments over Britain's role East of Suez.
In February 1967, he took a leading role in the opposition to the government's plans to raise fees for foreign students at British universities and introduced a Bill to give the people of Scotland and Wales referendums on devolution. This was as part of the Liberal strategy to draw the sting of the increasing popularity of the Scottish National Party and re-establish the Liberal position on 'home rule all round' with the Scottish electorate.He chose not to defend his seat at the 1970 general election. Laura Grimond fought it for the Liberals but lost to the Conservative Colonel Colin 'Mad Mitch' Mitchell.*
By contrast, Eric Avebury is a mere boy of 87.
* Some sources suggest he was madder than Mad Jack McMad, the winner of last year's 'Mr. Madman' competition.