Thanks for the replies fellas. I've come home and fiddled a bit more and I dont think the problem was as bad as first thought. I busted out the tape measure and the figures dont lie. Chainline appears to be approx 41mm front and back.

Think the problem was (a) my chain was a bit tight, (b) i squeezed the frame down a bit assymetrically and (c) my eyes.

Hopefully a chain clean/lube should take care of the remainder of the noise.

Thanks, Simon