I'm not sure about BL in the UK but Leyland Australia was all but shut down in 1974.
From being a full manufacturer (pressing steel panels here, manufacturing engines here) making several models - Mini, Moke, Marina, P76; assembling Land Rovers and Jaguars; making Leyland trucks and buses; just about to release the P76 wagon and Force 7 sporty hatch (Force 7 was to P76 what Mustang was to Ford Falcon) - but the Australian operation was in trouble with losses and a declining reputation, and increased competition from (Australian assembled) Japanese cars, so head office in the UK pulled the plug, shut down Leyland as a manufacturer and it became an assembler of Mini and Moke, Land Rover and Range Rover, plus importer of Triumph, Rover, Jaguar.
The assembly operations declined over time, by the early 1980s they got a contract to assemble Peugeot 505 for the Australian market. Before that, Peugeots were assembled in AU by their great rival Renault, but Renault Australia shut down local assembly in 1981 so Peugeot had to find another local assembler.
I absolutely loved the P76. My Dad almost bought one when Leyland Australia shut down in 1974 and left over stock was being sold off at half price. But they didn't have a wagon...By the early 1980s they were almost worthless, I got one when I was a uni student. The assembly quality of the early P76s was absolutely woeful, but increased soon to "no worse than other Australian-built cars..." There were jokes about them - "Leyland P38, half the car it was supposed to be" and so on. But in terms of safety, ride and handling, interior room, and standard features, they were well ahead of their opposition from Holden (GM), Ford and Chrysler. A lot of the criticism was valid, but a lot of it was BS from loyal Holden and Ford fans.
Handling and comfort were the strongest points of the P76 - a family size Holden, Falcon or Valiant from the 1970s (We had uniquely Australian cars called Valiant long after the badge disappeared in the USA) were rolly poly barges to drive, in comparison the P was nimble and crisp to drive.
in 1984 or 85 my Mum bought a new car and the family cars all went down a notch - I got her Renault 12; Dad got my P76 and Dad's completely clapped out XT Falcon was traded in on the new car. The P76 survived my Dad's complete neglect for several years, and he was very fond of it.