If I get a slightly older l322 (2010,2011 etc) I think I want it fully checked (turbos, oil pipes etc). I think it is beyond me, as I may do more damage trying to inspect/repair than any repairs I do.

Who would you recommend? SW ideally, London, north home counties next.

Or would main dealer be best?

With respect to turbos, there's not a lot you can "have checked". Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

As Alan said, there is no way to check a turbo or tell how long it will last, it's a bit like trying to tell how long a light bulb will last...

Just get one with a good history and make sure you phone the servicing dealer and check that everything that needed to be done was, they do a cheap service which is just an oil change.... they still stamp the book though.... Pete
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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

If you bought the right Full fat there are no turbos to worry about !

What like yours you mean ?  2021 L405 Vogue SE 4.4 V8 DIESEL ~ #17