Progress update,
On first fitting I discovered the floor / inner rocker repair panel had been mis-hit, it looked as though there had been in-sufficient set on the finish die so effectively it was too short on one corner, this meant the floor would not line up, it wasn’t a lot, but it was enough to be a problem. The simplest fix was to “stretch” it, so I cut it with a plasma disc, pulled it apart slightly and then welded up the gap.
With this done the floor fit was remarkably good and it was soon clamped and then tacked in place,
I have to replace the bottom 6 inches of the A post which is welded to the inner footwell. I find it useful sometimes to trial fit parts (especially re-pops) as a process of elimination. I trial fitted the inner footwell before I cut off the remainder of the A post. It fits perfectly so now if there are any fit-up problems after I repair the A post, I know it’s not this panel.