On Further Consideration...
....and some bat and ball with Learned Counsel, the fix for the cock-eyed front axle (moving the mounting holes) may not be the best way forward.
I measured everything again and arrived at the figure of 5/8" for the fore and aft discrepancy between the left and right kingpins. As mentioned earlier, my first thought was to re-drill the mounting holes on the axle and bump stops on the nearside and pull the axle forward by the required amount. That puts the axle in the right place for the tracking but the wrong place for the spring and consequently has an influence on the efficiency of the suspension on that side. I would also be pulling the offside of the axle slightly out of kilter so it's all pants really.
The other fix that occurred to me was to increase the length of the forward part of the offside spring so that the offside centre pin was moved aft by 5/8". I thought that was quite clever but Learned Counsel begged to differ, pointing out that it too would cause problems with the spring efficiency. Even moving each side 5/16" would still be a bit questionable.
Well, the only thing left was to re-visit the root cause of the problem which seems to be the nearside front spring hanger and the collision it had with the dry stone wall back in the Olden Days. There's definitely a distortion in the front of the frame but it's not one you'd notice unless - as I've now done - you start adding bits and pieces to the chassis that have to be ship-shape and Bristol fashion.
And the fix? To locate a suitable RSJ in a nearby building. I've got some stout bits of timber and Learned Counsel is going to pitch in with his 10-ton jack. We're going to lift the nearside front of the chassis - specifically the radius in the rail forward of the radiator mount - forward to where it should be and see if that works. Of course, there's a small risk of adjusting the building in the process....
The block of the Morris Six engine is covered in core plugs - 10 in all and a further 4 in the head. This is a good thing because removing them all has enabled me to clear out a biscuit tin full of rubbish from the water jacket. I left the head ones alone because in taking off the blanking plate from the end of the head, it looks pretty clear. The downside is getting the new ones in and watertight. There's 9 chances to get one wrong (the one you can't get at later probably) - the 10th is on the crankcase breather.
I borrowed the stud extractor I mentioned in an earlier post and with the application of some heat to the manifold studs (2 of which I broke in dismantling) to almost red-hot, a sharp tap or 3 on the end, the studs practically fell out. It's a brilliant tool and I've recommended to its owners that if their garage premises go up in flames, this is the thing for which they should dash back into the inferno to save.
No, honestly, it's that good (and there's a chance I might want to borrow it again).