Ralph, Thanks for the picture. Looking at the left hand side, it does appear that the engine mounting is further back than the right. You can see the gap between the nearest suspension turret stiffener and the edge of the engine mount is much bigger on the left. My engine mountings are in line but I suspect the left one is about 25mm further back to accommodate the steering pump. I located the mountings using the what I thought were the dimensions from the workshop manual but I now see that it was probably the dimension for the brake pipe brackets. As you might imagine I am now feeling something of an idiot, but at least I know what needs to be done.
Thanks for all the replies.
Tony.