Are there any Paternosters still functioning in UK? Good question. Dunno. They were certainly never that common, and I haven’t encountered any in my days since the afore-mentioned university (which have been many!).
Perhaps they all just went the way of Rutger Hauer in Blade Runner, quietly grinding to a halt while whispering “I’ve seen things you people wouldn’t believe. Attack ships on fire off the shoulder of Orion. I watched C-beams glitter in the dark near the Tannhauser gate. All those moments will be lost in time, like tears in rain. Time to die.”
I’ve previously mentioned the PN in the Arts building at Sheffield Uni. This building is about 19 storeys high, black, and the only tall building in its area. It looks not unlike an elongated version of the 2001 monolith, and at dusk it did tend to have a certain ‘presence’. Far as I can recall, though, it never did trigger any higher intelligence!