Eddie,
There were several canisters used on the willys CJ's. This is an image of Buddy Wade's '55. Does your cansister look like this?

I searched on KW and they offered a bolt that "fits all models" and doesn't look like the one above.
You could reach out to Harry Sheets,
http://www.midwestwillys.com/ , verify with him which canister you have and he'll probably have a bolt. I also noticed McMaster has similar bolts on their site too.
https://www.mcmaster.com/products/flange-bolts/hex-head-screws~/medium-strength-grade-5-steel-flanged-hex-head-screws/If Harry can't fix you up and you want to go the McMaster Carr route, I can pull my bolt out (same as Wade's above) and measure it.