I bought a Kincrome vice brake to bend smaller, thicker metal for brackets and the like.
This is some 3mm x 25mm mild steel, which is about it's thickness limit.
I had some brackets on my roof rack that looked like they previously had some kind of attachment and I thought I could repurpose. This is a bad photo, but all I have.
The roof rack is a Tracklander model and @Stropp will know the challenges of mounting things to the side of it!
I gave them a clean up and a coat of paint, and countersunk the top bolt hole and replaced the button head with a countersunk bolt for less obstruction.
I bent some clamps using 3mm x 40mm steel and achieved a rounder radius using a piece of 40mm x 40mm x 3mm aluminium U channel as the bend die base.
These clamp tight onto a compact shovel or I can move them onto the side of the roof rack to hold a long handle shovel.