MDJ,
Since your levels were normal and it's likely the Pravastatin that caused the increase, and you are no longer taking it, I'd think your levels could come down on their own with just the 6-MP. They didn't go over 100 so that's probably a good thing. You can also discuss with your liver doc about increasing the 6-MP before trying pred to drop your LFTs. How often are they checking your bloods?
You said "I feel I should stop everything"...what do you mean? Are you talking about the other BP meds? If your hepatologist is fine with those, then I would wait and see if your levels come back to normal with the statin out of your system. Does your heart doctor confer with your GI doc? I'm surprised they increased your statin in the first place. Are you also on a low cholesterol diet to try to help your cholesterol that way? I understand that sometimes gnetics is not in one's favor where cholesterol is concerned and meds ae needed to help lower it. And high cholesterol is bad for your liver too...double edged sword! I hope your levels decrease on their own...I, and so many others, share your concern on going back on pred!