I just finished reading the Vick Auto booster saga. I will avoid that if I can!
I am not sure where the leak originates - the plastic connector on the booster seems finicky to begin with although it doesn't have any cracks. I saw in some other brake servo threads a statement to the effect of brake fluid leaking into the booster, and it makes me wonder if that could be involved given the fluid residue inside the hose. I'll try to isolate further.