Another Key off electrical drain question

[moto67]

77 Cheyenne .. I'm getting a .40millamp key off drain. Pulled all the fuses .. still getting the drain. I took the horn relay off since I have no horn at the moment.. that didn't help. Unplugged CD player.. checked cigarette lighter wire.. and as many other wires I could find. Someone said the main electrical junction on the firewall was dirty on theirs and was causing a short. Mines filthy too.. going to clean that up and see if it helps. I don't think that's it though. Thing is driving me crazy. I have a new battery and new alternator. It's charging fine.

any other ideas?