Yes, the major British motor manufacturers of the time and trade unions ensured that Joseph Lucas did not supply to minor manufacturers. I once spoke to an elderly gent at the NEC (not John Meadows.....) who used to be high up in Lucas and he explained with reference to our minority manufactured cars why Lucas could not supply until 1958-59. The Frisky Sport is the perfect example, designed to have Lucas pre focus headlights but production cars had to be fitted with Wipac and a terrible white rubber ring to blend the body profile to the slightly smaller units.
Wipac is reasonable but all the others, LEP, Stadium, Sparto, Raydyot where all after market accessories and of much poorer quality.