So, I pulled apart a polar express, and my NW2, which uses the same smoke unit as many other LC+ engines including the Berkshire. I don't see any reason one couldn't fabricate a new metal bracket to hold the blower unit instead of the puffer and perhaps a piece of foam to make a nice seal around the stack. The electronics are a bit more annoying as the polar express engine doesn't have any method to vary the fan speed or to match with chuffs in it's design. One could wire the heat element and fan directly to the same power used for the puffer, but this would spin the fan at full speed whenever the engine is moving, and run at full heat, quickly using up smoke fluid. I think it's possible to build a small circuit to tap into the chuff sensor to spin the fan in time with it, but that may be beyond what the OP is looking for.
Edit: come to think of it, I think that's exactly what GRJ's super chuffer would do, wouldn't it? Maybe with some hacking to use the LCPE's opto sensor and not disturb the original electronics.
