Here is a older Power Tank Off Road 20lb Co2 Tank Mounting Bracket model # BKT-2274 it appears from there website they no longer offer one for the 20lb Co2 tanks but still shows up on the web.... The mount is aluminum and holds any 8'' diameter tank the mount is 14'' long comes with stainless mounting hardware...
The straps could be shortened to mount a smaller 10lb tank as well...
It has been mounted but never used off road...
From there website:
CO2 Tank Super Bracket Lockable Straps 20 Lb 8 Inch Diameter Aluminum from Power Tank. 20 Lb. CO2 tanks are monsters. They weigh 50 lbs. full, stand 30 inch tall, and are 8 inch in diameter. These tanks need to be held securely in your vehicle or trailer and we have the bracket for the job.
This bracket sports two quick release straps with lockable latches. The frame is all aluminum for strength and weight saving. Rubber strips protect your tank from wear. Multiple mounting holes make mounting easy.
By the way, These brackets also work with the taller 50 lb. tanks or any other gas bottle that has an 8 inch diameter.
Asking $75
Jeep TJ YJ CJ FJ40 Bronco Rock Crawler Rubicon 4x4 Chevy C10 Ford F150 F250 F350 Dodge Scout M38a CJ2A CJ3B Off Road Dual Battery 4x4, 4wd, Toyota, Landcruiser, Land Cruiser, FJ25, Fj40, Fj45, FJ47, FJ55, FJ60, FJ80, Diesel, 2H, 2F, Transmission, Transfer Case, Off road, Rock crawler, Jeep, Willys MA, Ford GP, military Jeeps, CJ-V35/U, M715, Off-road, Jeepster, Jeep FJ, Jeep CJ, Jeep DJ, Jeep SJ, Jeep Cherokee (XJ), Jeep Gladiator Rubicon Moab, Jeep Comanche, Jeep Wrangler, ZJ, WJ, WK, XK, KJ, Chevy, Ford, Dodge, GMC, Chevrolet, Auto Parts, Truck parts, four wheel drive Trailer Car trailer Toy Hauler