Have recently replaced both the wishbones, CV joints, bushes and brake caliper pins (the latter just because they'd sheared off so had to bore them out), suspension "looks" fine, any other ideas? Its not there all the time, just when theres a slight bump in the road, or a large pot hole! Fixable or do I put up with it?

Have you checked the suspension leg and spring? Mk1s seem to crack springs.

The MKI also eats the front ARB drop links pretty regularly. 

Have you checked the suspension leg and spring? Mk1s seem to crack springs.

Yes suspension all seems fine, Will have a look at the anti roll bar next, Although I replaced both of those last year so didn't think that they would have gone already.

I had a similar issue last year, and it was the right hand rubber on the anti-roll bar. Try to move the bar near the rubbers and see if there is any play.

I have located the problem to the bolt that holds the arm onto the sump. Now I need to find a way to re-tap the bolt or get a new one but the thread in the hole has gone too and there is no nut to connect the bolt to sigh.....