"Tea Mr Shifter" Is from a PG Tips advert from the 1970s when it showed some chimps (Shifter and Son )carrying a panio down the stairs when the panio falls down the stairs.Best line"Do you know the panios on my foot?You hum son and I'll play it. Uncola I dont know.
I'm in the US so I may be incorrect for the UK audience, but...
I recall 7-UP calling itself the "UnCola" way back when I was younger. They had glasses designed to look like upside-down Coca-Cola glasses and everything. I know they're onto the "Make 7 Up Yours" now, but I still think of them as the UnCola!
As for "the pause that refreshes," that's a VERY old Coca-Cola slogan. I still find it mentioned now and again, so that may be what you've seen.
I hope this helps!