Would really like to know exactly what it was that was leaking.
HAPPY for you that the dang thing isn't leaking anymore!
I don't think it's leaking anymore because the tire pressure I just read isn't lower than it was 16 hours ago. I'll know for sure when I air it back up to 50 psi.
This is my current setup:
I'm using the existing air pipe and elbow, and installed a 3/8" x 1/4" bushing with a 1/4" x 1/8" bushing installed in that, with the original 1/8" Schrader threaded into that. Everything has Permatex thread sealer applied. Despite that, the leak was at the 1/4" male threads. Fortunately just turning that fitting a quarter-turn seemed to solve that - we'll see!
I did it this way because my closest hardware stores don't have 3/8" x 1/8" bushings in stock. So I created an additional leak point because that's what was available at the time
I found that Lowe's actually has them in stock a half-hour away, so I'll be making a trip out for them soon. Moving forward I'll be cutting out a leak point with the new bushings.