Going on the advice i've had to date, unfortunatly its not as easy as just fitting shells. Early 6LWs were fitted with thick walled bearings that had to be line bored in position, later models were fitted with shells. It may well be possible to upgrade to LX rods, and convert to shells in the case of the big ends but the mains are dictated by how early / late your crank case is. As far as i can establish NOS thick walled bearings are virtually unheard of now, and shells aren't too common either. I've tried a number of places including gardner spares, with the advice generally being to get it pulled apart first and figure out what i've got and what state its in, so guess thats the first step, i just wanted to see if anyone else had any experience of doing it themselves, because i like to do things myself rather than shipping them off for someone else to do. I will definatly contact this Cox & Turner though, Tintinhull is very close to me.
Thanks all for your input. Richard