The "Callaghan calls an October '78 Election" POD is probably too late. Even had Callaghan won an overall majority (which is likely but far from certain) he would have faced 20-30 Bennite backbenchers, a Bennite controlled Labour NEC and a trade union movement where the likes of Scargill were rising to prominence. He wouldnt have the political space to manouver into a Hawke-Keating style accord with the trade union movement, the rot had gotten too deep. Even if Callaghan had been able to successfully hand over to Healey in 1980-81, Labour's chances of re-election aren't particularly good.
Labour winning in 1970 is one plausible POD. With Wilson not having to struggle to keep Labour united in opposition - and Benn still in government and not shifting to the left post 1970 defeat as in OTL - its likely Gwyn Morgan takes over as Labour General Secretary in 1972 instead of Ron Hayward (Hayward was elected in OTL by Wilson's casting vote). As a consequence Labour's proscribed list is upheld, and fringe far-left groups, particularly Militant, are never able to find their way into the party. Jenkins/Callaghan succeeds Wilson as leader, but the 1973 oil crisis means the Tories win the 1974-5 election. If Labour stays together in opposition theres a good chance Labour could return to power in 1980 under Jenkins, Callaghan or Healey.
The most likely scenario is what if Heath had won a working majority at the Febuary 1974 election. Wilson, expecting a defeat, had already decided to resign as leader after the election, and would almost certainly have been succeeded by Callaghan. Instead of exhausting himself holding together a government with no overall majority as in OTL, Callaghan is in opposition, and has the time and political capacity to take on the hard left. Instead of Labour tearing itself apart in 1979-83 however it occurs in 1974-78, at a time the left doesnt have an unpopular moderate Labour government as a punching bag. Labour loses the 1978 election (assuming Heath is better able to manage the economy, particularly in 1974-5, and the city not being spooked by a Labour government butterflies away the 1976 IMF crisis), but 13 years of Tory government and another oil crisis means Labour win the 1982/3 election, perhaps by a small landslide. Labour would have the benefits of a relatively easy economic ride, north sea oil money, and the 1971 industrial relations act is never repealed. Labour would probably be in for a couple of terms. Most likely by the 1990s Britain is looking a bit like West Germany, a blend of social market economy, reformed trade unions with large memberships, efficent and publicly owned rail and bus networks, a coal industry that is in decline but will be phased out over 20 years or so rather than overnight. Maybe this 1980s Labour government privatises British Airways, Rolls-Royce and British Leyland, and perhaps sells some shares in BP (Callaghan sold a minority stake in OTL), but the more controversial Thatcher-Era privatisations, Water, Gas and Rail are certainly not going to go ahead as in OTL.
