Armor Shooting Bench of Havre, Mt uses an almost identical unit to Claimbuster.
The gentleman at Armor shooting benches would sell you the angled braces for$20 each.
the secret to this bench is the 4 legged model, with 1 1/2" plywood. It is so sturdy that you could set a 4oo lb Buffalo Heffer up on it!@
I went through making benches. You need a thick top, so that when you move our elbow just the slightest, that the weight change does not effect your point of aim.
I put four large handles on the sides of the benchtop,and it is easy to move. Legs screw out.
I found that my shooting was dramatically improved if I could get my right elbow down on something solid. If my elbow is flopping in the breeze...my shots are all over...must be a birth deffect.