Re: will this gas tank locking cap fit?
You can buy a new gas valve from Napa. I have used several on different builds to replace the leaky cheapo ones that come with the kits. They have 1/8 " pipe threads. I use a little gasket sealer on the threads.
Reserve? I never saw a kit that had a petcock with reserve. Most of them don't actualy shut off the gas completely, so maybe that fooled you into thinking it had a reserve position.