While I haven't been to the Ima, Thomas Fraser route for a few years..(I have attched the photo with the new add photo feature on this site! Nice job guys.) I distinctly remember stopping off on Hatchet to fish Walleye, there is a nice shelf around the first point on the left as you go down the lake, might be a nice diversion from cranking deep divers for lakers.
On the lakers... We had success trolling large shad raps and dr. spoons across Fraser in depths as deep as 40 feet...we would add split shots 18-24 inches infront of the lures to get them down. Also night crawlers on heavy jigs in 50-75 feet mid-day. Nothing like a 2-3 pound laker roasted with butter and onions in a bed of coals for a good evening meal.
Luck,
Whiteman