77 360 Holley 2245 2bbl question

I've got a 2bbl barrel off a 360 that I'm rebuilding, and I lost the keeper off the power piston, shown below at the bottom on the air horn.

(not my photo)

2245%20power%20piston.jpg

I have found a washer that will hold it in place but I want to make sure it will work. Am I correct in understanding that all that keeper does is hold the piston in place so it can be flipped over to put the airhorn on the carb body? I don't see anyway that it really seals anything.

Also, that's supposed to be staked in place using a special tool or a tiny chisel and try to not mess anything up. I don't have the tool and have had no luck with a chisel, so I wondered if I could just glue the thing in place with a little JB Weld, if I'm careful to not get any on the piston that would limit or restrict its travel?

Thanks for any tips,