Welcome Dan, is that a Black Flag tatoo i spy?
It seems your problem is more the saddles than the actual bridge. Im surprised filing a deeper slot has'nt worked.
There's a few options;
1/ Increase the string angle over the saddles either by using a 'buzzstop' or shimming the neck and hiring the bridge.
2/ Or try different saddles, maybe roller saddles
3/ Try a Mustang bridge
4/ Try a 'Mastery' bridge.
Personally i'd try them in that order too, each option gets more expensive!