The CJ3A/B tanks are under the drivers seat and are simple in construction which means they won't work for what you have in mind. Unless you have LARGE holes, I would suggest removing the tank, cleaning it as best you can and using a commercial slush/sealer on it. 1 qt should do 2 coats and don't forget to protect the fuel line outlet so it doesn't get plugged up.
Don't even think of using a torch to mend holes before using the sealer - tape, Bondo, resin, JB Weld are better solutions. I had to try a torch on a tank one time because the solder joint that attached the fuel line outlet to the side of the tank was cracked. Even though I washed the tank with gasoline, then MEK and twice with water and detergent, some fumes from old gas were still present and ignited - with a loud noise and a flame that shaved off the hair on my arm. The 2nd and 3rd ignitions were milder.