Chasing Leaks: The Leakening. This time it was from the regulator gauge. The Rainson doesn't have a pressure relief valve; you can unscrew the bottle then let the air out of the regulator through the regulator gauge. Seems like a pretty jakey way to do this, but maybe I was spoiled on my Avenger. Anyway, there was a 20-bar/day leak that was coming from the regulator gauge. I remembered as I was looking at bubbles that you don't hulk down gauges with delrin seats, you just tighten them hand tight or a smidge tighter.
I did also remember that some other Rainson owners said you do need to tighten bottles a touch more. Keep a strap wrench handy and tighten it a little past hand tight.
The downside to a hiatus is that you forget things, especially at my age. Memory is the second thing to go and all that.