I pass a Milk & More depot on my travels through the steppes of South Croydon, so I guess it's a thing even in the Big Smoke. That said, not seen anything more local. Milk delivery was a big thing when I was growing up, of course, mostly to support the 'he looks like you he does' meme used when defaming someone's parentage.
I'm not sure, to be honest, who needs so much milk. I'm sure we used to get several pints a day back then. We get a box of UHT semi-skimmed and it lasts for ages. Perhaps they bathed, like a cheaper version of Cleopatra, in gold top.