Really!!!! sub standard repair.

genius love the use of the dial guage nice
sound like you have it sussed way better than i could.... i'm much more suck it and see...... more time spent on correcting disasters than driving :)

you could run a bigger bumpstop for the top arms

if you can find A body big block torsion bars they may help must be someone in the UK who took em out to replace with slant bars to go racing....
dunno which way they are offset at the hex ends
i.e thin bar more offset
fat bar less
or is it the other way round??

basically
does a fatter bar bias the suspension into bigger droop or is the hex offset less with them becasue they twist less at standard ride height... Dunno. someone will..

full force of a torsion bar aginst a modified bumpstop is what spoils my suggestion i guess.

coilovers into the top front shock mount might cause the Mk2 ford cortina issue
i.e streight through when you least expect it..... hard to tell when the things were not made for a macpherson strut.

Dave