Good luck with the £10k targa. Bodywork most likely going to need a lot of attention, very rare to find even a good one that doesn't need sills, wings, kidneys and possibly a lot more to boot. I saw a G50 which started its sale price at £27k last year but I stopped watching price drop when it hit £16k. When I viewed it (at £20k), it had needed serious underside welding just to pass the MOT. There was rust everywhere. Add in possible engine, clutch and gearbox issues, plus interiors are expensive to put right, and the chaps are spot on - you will soon find you have spent £20k to make it right. To read the full horrors of what I found in my search last year (viewed almost every sub-£20k SC and 3.2 for sale I think!), head over to Impact Bumpers and look for the thread "Wanted - SC or 3.2" in the Wanted section.
Hope it comes good for you!