You could be right there John ... they certainly were responsible for increasing standardisation of international copyright laws.
I have three of the Marginals, all bought from that Oxford Circus HMV .... Chris Clark, Monitors/Elgins, Choker Campbell/Earl Van Dyke ... plus one of those "Detroit" compilations on Marginal's sister label Bar. They only seemed to be available in that HMV store for a few weeks so no doubt Motown's lawyers leapt in there quickly.
Roger