I think your right, I know what DS is saying, but I think these cars go back before that and none seam to have been stripped of anything (I know they have now but early shots show them whole)
Yes they all go way back before anybody had dreamed up 'Environmental Protection', but by the time the Act was fact they had become, like many of these good intentioned collects around the UK, very expensive restoration projects or rusty scrap. Obviously which category one views them depends on your interest in the classic car movement, and it does not take much grey matter to work out what the LCC's brand new EP department's take on the subject was.
Sadly two of my favourite haunts as a mobile teen - two collections started in the mid 30's that eventually expanded into junk yards containing vast arrays of cars, ex MOD and other wheeled transport and much besides - fell foul of the act and ended up in the scrap furnaces. Fortunately my rescued 1938 Ariel 500 is still going strong!