thanks for that Lewis, that's a pretty substantial solution! Can you let me know what gauge steel you used there? Did you have guidance that that's what is required, or were you taking a belt and braces x1.5 approach?
On the shoulder mounts did you check teh height of the mounting as per Snapper's post above? According to the IVA I'am about 2" too low to mount directly to the interface of the tub/roll over bar (where I marked o with teh blue arrow on my photo), - one thought I had was welding a cross member to the upright stanchions of the ROB, and mount directly to that