Roll Bar too

[voucht]

Hi,
I'm in a deep sh...t
I just finished my roll bar.

IMG_2751_1.JPG

But I have a problem: after fully weld the cross-bar, it looks like the whole thing shrieked. When I tried to fit the roll bar fully welded, it looks like each RB1 plate moved inward of about 3mm. So I can't bolt the roll bar on the chassis, it is of course not flexible enough to match CP3/CP4 hole pattern.

IMG_2747_1.JPG

However, to put everything together, I made sure that:
- I drilled plates RB1 at the same time as CP3/CP4, to make sure both hole patterns will be exactly the same,
- I tacked the man hoop on RB1 with RB1 bolted to CP3/CP4 on the chassis to be sure they will be exactly where they should be,
- I tacked the cross-bar and the back stays in the same way.
But I should have fully welded the roll bar with the plates bolted to the chassis too. I didn't expect it to move so much after being tacked.

What do you guys think? How can I solve the problem? I really don't want to cut RB1 plates off and weld new ones. I'm thinking about making “oval” holes on RB1 to match with CP4 hole pattern, but as the roll-bar is holding the seat belts, is this acceptable?
Any opinion, advice or comment is welcome. I'm so pissed-off
Thank you.