In response to DrTerry's and DrJohnWright's comments regarding the ZA vs ZB power steering, as luck would have it I've just been looking through the ZB brochure, which states "including a new, more direct ratio power steering". So it would appear that there was indeed a difference between the two. If I recall correctly, the ZB, ZC and ZD all had the 16:1 "GT" ratio steering box, with power ram assist of course. Not too sure what ratio the ZA would have been. A great episode!