Naw, spoke too soon. I can't solve this one. All o-rings replaced several times, tried a couple different washer configs, multiple pressure settings, but still get varying levels of leaking through the weep hole. I'm assuming it has to be related to either the small o-ring on the adjustment screw, but this is less likely I think. Primary suspect is the o-ring on the piston. FX asked me to send if back again, but this would be the third time to them after a prior repair by the dealer. They did send me a replacement piston assembly (included o-ring), but no difference. Assuming this is the trouble spot, any thoughts on the brass bushing? Other thoughts are of course welcome. I've also replaced the 4x1.5 o-ring in the body of the regulator. I used NBR 70, assuming that was correct. I'm not sure how much pressure that even sees, it may just aid alignment of the piston. FX said they don't have any bottle adapter assemblies to swap with me at this time, but maybe I should wait for that. Appreciate your ideas. Thanks.