Trev,
I used to live in Royal Oak for three years when I was at school in downtown Detroit. next time I am up your way, I want to come over and see this beast!
Have you maybe tried just dropping in live feeders at the exact same place in the tank every time? I have to think that if you held the feeders while alive half in the water in the same place so he had to come up to you to get them (and after a while, he would), you could then start to filter in a few pieces of shrimp in with the feeders. Eventually he'd recognize you as his food source, as mine does now, and when he sees that I have something white in my hand he knows to go to the upper part of the tank and wait for me to drop the shrimp in now.
I think this would work for you.