I agree they were good engineers, but come on... Fenders and Gibsons weren't exactly rare in the UK after the mid 60s. Most 'name' bands had them. By the mid-70s, they were being imported full-scale and the British builders can't possibly have been unaware of them. The British guitars were still cheaper too - but they never achieved real success purely because the designs weren't right.
Of course, Fender and Gibson did the same thing in the 70s as well! In some ways, those much-maligned late-CBS Fender and Norlin Gibsons are the Big Two's "British guitars"... actually quite well made - at least in terms of materials - but just *wrong*

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Though curiously, my Les Paul Signature is totally *right* - it just doesn't look it at first. Likewise the Fender Starcaster.