In this movie, Harris and Proctor go to the Blue Oyster Bar. Proctor says to Harris that Mahoney gave him the directions. I think Proctor brought Harris there on purpose.
Because in the 2nd movie he knew the address and in the 3rd movie he ended up in there naked by accident.
Remember... Proctor isn't "playing with a full deck"... Because he doesn't "Play Cards"!
But in all fairness, to Proctor...
It seems that the Blue Oyster Bar moves around from movie to movie, and also has numerous entrances too...
In the Second film, all of the Skullions are placed in a truck parked on a main street. In the Fourth film, Harris and Proctor, enter the bar from an alley. Most business don't have "mailboxes" in alleys. Besides, Proctor got "Directions" from Mahoney. That doesn't mean he was given an "Address".
"Nice Uniform. Makes me wish I'd worn my sailor outfit."
"Put A Little Love In Your Heart, and then Make Your Own Kind Of Music, on the road to Shambala!"