Had to chuck the old one out as the flow screen thingy at the outlet had totally disintegrated resulting in messy spray.

What I thought an easy job turned out a bit tougher.

The Q: How can I ensure that the new fitting would tighten at the 12 o'clock position as it won't now: it tightens around 4 o'clock which isn't any good.

Hope this makes sense, anyway this pic might help:

Pic shows it at 12 o'clock leaving fixture a bit floppy and slow seepage where it mates the blue PVC part.

Thanks for tips.

More PTFE tape, then some extra.

Really! lol

I run out to the shop get more tape.

Thanks!

Add/remove tape to the back of the threads until it starts to tighten just before you get to 12.

Tap needs tape

The metal to plastic threads are very tape hungry,

Plastic thread worn out, not precise in diameter ...

Thanks to all for tips.

Got myself more tape and after a couple of tries managed to get it to sit firmly vertically and no more seepage.