Jack Nicholson
Just watched this movie for the first time, and OMG what a look-a-like I found.
0:29:38 - the public toilet sequence there's a guy walking by Jeffrey, dressed in a blue shirt. He's a spot on Nicholson!
Damn, you're right ... he does look a lot like Nicholson!
On my Blu-Ray copy, he shows up around 0:30:53 and he kinda looks like a cross between Jack Nicholson and Larry Fessenden.
"Stwike him, Centuwion ... vewy Wuffwy!"