Hi Sean,
the photo of the pistons as Kevin pointed out - looks as though the pistons are different.
1 x flat top & one with a swirl recess.

Or is it a trick of the light??

The correct pistons have valve & swirl recesses off memory.

I haven't had the misfortune to attempt an oil pump on one of these yet, but it may be worth perusing the link below - as they seem to be a tad nasty.

http://members.boardhost.com/ukautotalk8/msg/1239346267.html

As Peter Sokolowski point out in the last post, the turbo's are prone to failure after oil pump failure.

See here -

http://members.boardhost.com/ukautotalk8/msg/1307635395.html

Looking like a can stuffed full of worms from where I sit??

hth,

Jon.