Roll bar fastening

[TheArf]

Ok I don't know if this is the right section to be asking this if not please forgive.
Right, I'm looking to fit my roll-bar to the car I have had the bar made by a local company, but we won't go into that it's a sore subject, my question relates to the support bars going backward. Could I fit a couple of suspension brackets to a plate welded in to the two box section uprights, the ones that are vertical between the rear hoops, and then fit a bolt through the tube. The brackets would be welded to the plate.
I seem to remember that they would not allow the original design saying that it needed two bolts to anchor the rear stays.
Does this make sense or does it seem like I am talking a load of twaddle.

Arfon