Malaysian Airlines System actually operated the 707 and DC10-30s to Europe until the arrival of the 747-200Bs in 1982.
Flights generally operated via Kuwait with one of the flights operating via Dubai.
Indeed most flights (if not all) bound for London made an additional stop at Amsterdam, Frankfurt or Paris enroute to Heathrow.
Flight numbers were MH1/2/3/4/5/6 (depending on the stopover city in Europe - AMS
being MH1/2, FRA
being MH3/4 and CDG
being MH5/6) if memory serves me.
From the 1980s onwards - the 747-200Bs gradually took over from the DC10-30s and the middle-east stopover eventually standardised to Dubai.
Hope this helps.
British Airways meanwhile operated the more popular flights via Bahrain, Muscat or Bombay between London and Kuala Lumpur at the time - operating a mix of VC10s, 747s and from the 1980s the L1011 Tristars.
Flight numbers were BA889/BA888 and BA9/10 then operations slowly became more combined with Singapore operations as BA11/12 and BA11/14 (operating to Brunei) before becoming BA32/33 when the Tristars tookover the route.
British Airways and Malaysian Airlines System actually code-shared in the early 1970s for those who were unaware.
On a related topic - in fact - Qantas operated the fastest Sydney-Kuala Lumpur-Bahrain-London 707 V Jet service in the late 1960s/early 1970s and at the time reigned supreme on the KL
I still remember the very last Qantas 747 service from London arriving at Kuala Lumpur Subang Airport as a boy - my family were travelling on that very flight as there were no further flights available from London with QF
after that evenings arrival (so they had to book on to that service and avoid the hassle of reissuing tickets - which in those days meant tedious trips to the Qantas office in London i seem to recall)!