It can take years for a record to eventually make it "big" nationwide or shall I say gain exposure to a wider audience. One of the records you mentioned which you claimed to be a Burnley sound and not an oldie was played many years before by at least two other Dj's and in that respect is a bit of an oldie and was widely known by those who attended the 100 Club, Lifeline and other venues the two said Dj's appeared.
Was it Cliff who played it at Burnley? He no doubt, knowing Cliff, had it tucked away for years before giving it turntable action. This and the fact it is an obscure and tough to find record make it hard to gain wider exposure on the scene. Butch's Parliaments another example. It wasn't until the likes of Sam and Mick got copies and played it up an down the country that it broke nationwide,I could give other examples but it would be pointless.
As for who cares who played what first, many do, I for one like to see respect and credit where it is due. As for playlists most no longer post them not just because they get picked apart but because all the lazy sods then go and hoover up the records listed that said Dj has worked hard to find, put the hours in, if they wanna know what a DJ plays go out and listen to them.