Yeah there isn’t, the closest to that would be the 370 and 372 if the 370 curtailed at Hornchurch Town Centre.
Off topic a bit, but I've not seen the 372 stand alongside the 252 at Hornchurch. Does it stand elsewhere?
372 terminate where the 252 starts towards Collier Row, it then stands down a small road, I have seen it turn into its stand and come out but never have I went in and actually saw where the bus turns around. But the stands are different and the 372 starts just in front of where the 252 terminates.
No because the 27 and 70 don't terminate at the same terminus at the other end. The 27 terminates at Chalk Farm and the 70 terminates at South Kensington. This thread is about bus routes that have the same terminus at both ends. like the 143 and C11 both start at Brent Cross and end at Archway.