I'd never seen a method of support so I had to make it up.
|Long studs and cross member|
I made two elongated studs threaded with 1/2" BSW at one end and M12 at the other (Metric is cheaper). These were able to fix in place the 'hoop' bracket whilst allowing the cross member's height to be independently varied to suit where the pipes need to be in the cab.
In the picture, I didn't know what height was needed so both lock nuts are below the cross member. I'd planned to have one above and one below but may not have got it quite right. Obviously I did the nuts up a little too tight at one point as the no-longer-nicely-rounded 'hoop' shows!