Some good progress there Ginge
I am amazed at just how clean & bright your chassis still looks, You must be working in a dry enviroment .
Don't beat yourself up about the roll bar pulling a little when you welded it.
Unfortunately a weld of this type is going to pull ........... I would be more concerned if it didn't
If the mounting plates have pulled inwards by only a few mm it's nothing a small trolley jack & sturdy bit of timber wouldn't sort out.
Give it a gentle tweak, it'll not stress the weld too much.
If they have pulled outwards a sturdy ratchet strap will do the job.
Looking good mate