Try napa. What exactly did you screw up? On the 2G there are 2 parts to the power valve, the piston and the valve it contacts down by the jets. The valve part by the jets came in a rebuild kit I bought from Kanter auto.
The power piston consists of a metal piston, a retainer ring, and a spring. I don't think anything but the spring is available anymore. This part attatches to the air horn. The power valve system is responsible for providing a richer mixture during the low vacuum situations like acceleration. It bypasses the jets. It helps fuel economy and prevents knocking.
You may have to get an extra junker carb and scavenge the part. Good luck.
1955 Willys CJ5 Buick 225 V6 160HP 270ft-lbs, T90 trans, Warn OD, PTO winch, Spicer 18 T Case, RS9000's, Dana 25F/ 44R,
5.38:1 gears, 11" brakes, Bestop Supertop, Hurculiner