Have considered welding the roll bar in place, so might go this way now. Did not think about using nylocks at the time. Bumma!

Still I am sure he will be happy if cage/roll bar is fully welded.

Nothing to stop you, just easier to remove if you had to or wanted to modify it or anything in that region.

I used 10mm bolts for the mountings as oposed to 8mm and domed plated cap screws for the top mounts.

Box in the mounting plate as well to give it extra support, last thing you want is that bit of 3milly plate bending in the unfortunate event you need the roll bar to do it's job.