I wanted something a little cleaner for fire extinguisher mounts than the zip-tie/hose-clamp/bungee cord approach I’ve used in the past.  These are just a metal fire extinguisher mount welded to 2” exhaust clamps.  One will mount horizontally and one vertically - on the vertical mount I added a piece of strap steel with a right angle at the bottom to give the fire extinguisher a foot to rest on. Cost was $10/each.  Just need to sandblast, paint and install.

The hardest part was finding the metal brackets - for me a stop at a semi truck supplier was the key.