Sorry...for lack of a better way to say it, I wasn't actually able to look at the setup yesterday for I was out of town and couldn't remember what this actually looked like. I just was able to figure it out I believe. It's threaded, and I believe there's no bushing involved. I've attached a picture (never mind the two hoses, one's simply a temp drain hose I rigged), and was able to drain the tank to get a clearer view of what's inside the tank itself.
The valve mounts onto a "rounded square flange" on the bottom of the tank, and I can see the barest of a single thread where the valve mounts to the flange itself. Then after draining the tank, I was able to see clearly the threads in the inside.
After looking at the area...there's no way a bushing is in there. So I'm assuming the bushing and unthreaded valve as you say simply "snaps into place" in a round hole on those style tanks. The leak itself is the valve...when closed, no leak. When open, the turning knob ever so slowly fills with gas and acts like an upside down cup - I then turn the knob to close the valve, and the gas then gets pushed out (or the knob fills up with gas eventually if not closed and still leaks). So...I know what to order now
The reason I was confused is when I look at an exploded view of the H70-130067 on Parts Tree's site, it looks to me it thinks the bushing goes with both styles of valves.
dbert, thx for the help - when you mentioned "snap in rubber bushing", the light bulb went off that there's no way a rubber bushing would work with a threaded valve.