Identify coolant pipes please

These coolant pipes were purchased at a clearing sale near Tocumwal, NSW, Australia. They are copper, British with Avimo coupling flanges. There were a number of Mosquito bits with the pipes that drew the conclusion that the pipes were from a single single or two stage Merlin. In going through the schematics for single or two stage Merlin for Mosquito the shape of the pipes don’t seem to fit. Tocumwal was a major scrapping centre for the RAAF and it is delightful that these copper pipes have survived, as the red metals were the first things the scrappies seemed to process out. The pipes have a PP code, eg PP1234 and a lime green paint colour. I would be grateful if anybody could recognise what aeroplane they fit to. Anybody who can match the PP code with a parts list or particular pipe to a drawing and post this for definite proof will win a packet of diabetes inducing doughnuts* or 5 minutes of free advice on teeth whitening options* or the option to enjoy our new WW2 re-enactment experience ‘fitter scrapes asbestos cladding off coolant pipe’. Limit one pipe per person.

So here they are :

[ATTACH=CONFIG]248911[/ATTACH]

The above has an aluminium valve or coupling in the middle with ‘vacuum’ inscribed on it.

[ATTACH=CONFIG]248912[/ATTACH]

[ATTACH=CONFIG]248913[/ATTACH]

[ATTACH=CONFIG]248914[/ATTACH]

The paint colour on the pipes is Beaufortish :

[ATTACH=CONFIG]248915[/ATTACH]

*doughnut offer excludes icing if this is tasty. Judges may combine doughnut and teeth whitening offer if they deem this prudent for you.