Original Template
I made a template from an original tank holder. This is a trace of the original hardware:
Newly Built
Using some thick steel and a vice, I bent the steel into shape.
With J-bolts and and nuts:
...
Revised and Painted
I changed out the tightening mechanism . Easier with the turnbuckle instead of a nut on top.
I will paint them eventually! 
Painted!
to use a turnbuckle.
