Finally got the Phantom running properly again.
After fitting the new bottom shell it was consistently losing signal at random places, not distance related.
So it was pretty obvious something was wring with the antennae when I refitted them so stripped it again. All seeme ok but to be on the safe side I bought a new set landing gear with new antennae and compass leads in. Signals all sorted but a dreadful rattle when flying into the wind or pushing hard. Had a look and found that the props whilst fixed on OK were very loose. Spare props were better but got a new set of prop mounts and low noise props frome Heliguy, 24 hour service, excellent.
Fitted taking care to replace the dotted monts with new dotted onesand tested it. Would not lift off. Turns out that the dots are on the opposite mounts to the originals even though the new ones are genuine DJI. Changed them round all all finally working as it should again.
The old mounts were covered in white dust, obviously where the mount and prop were mating and wearing away causing the loose fitting and the rattle.
Mount covered in white plastic dust