I recently purchased a second hand President's Choice DC Controller from my LHS here in Toronto. No matter how hard I tried, I could not find any information regarding it. The model indicated is F352 and some information regarding this will be greatly appreciated. I never knew that President's Choice made DC Controllers!
You are right, the train sets are made by IHC/Mehano specifically for Loblaws/Canadian Superstores. These are special order items designed just for the Christmas season. I would suggest you "google" the companies.
The controllers sold with President's Choice trains the past few years has been a two piece affair. One piece is the power supply, a wall wart that converts house current down to something around 18 volts. The controller itself is a single knob unit with a twirst - you have to turn it all the way counter-clockwise until it clicks in order to change direction.