BigWallop ) gurgled happily, sounding much
like they were saying :

Sounds like an old lead water mains, and the bit you see is the old
stopcock and wipe joint. The thread will be something like 1 1/2''
BSP size probably.

So off I go on a wander round the likely sources...

Stop 1. Bathroom store with a damn good plumbing trade counter round the
back, staffed by ol' boys who've bin there, dun that. No, the trade
counter's closed down, and the showroom's extended into the space. Soddit.

Stop 2. Jewson. Spotty git hasn't a clue, and half-heartedly tries to sell
me some plastic waste pipe fittings, because they're the only thing that
sort of size he's got. Try Plumb Centre.

Stop 3. Plumb Centre. Spotty git hasn't a clue, and half-heartedly tries to
sell me some plastic waste pipe fittings, because they're the only thing
that sort of size he's got. Try... umm... somewhere else...