The Big Country wireless remote brain on a 3450TS is located inside the cold air return vent above the closet, next to main entry door. Remove the wood vent, unscrew the panel, and there it is.
Unsure about the LINC system. This is a different remote and I am unsure if it "talks" to the current brain installed in the Big Country. If it does, great, please let me know!!!
Hope this helps.