Here are a couple options. Wallys Tackle, 3195 Sandwich St., Windsor, Ontario, N9C 1A7
Phone 519-256-2841. Sandwich St runs along the river and Wallys is just west of under the bridge. After going thru customs, turn right at the first light(McDonalds) go to the next street and turn right back towards the river to Sandwich street.
In Belle River, the Co-op Gas station has 8 day non-resident but no annual non-resident.
The Variety store at Lighthouse Cove(Thames river) has annual non-resident license.
I've heard that Canadian Tire on the East side of Windsor has Non-resident license, but I don't know where it is.
The Deer Brooke Marina is under new ownership and doesn't have Fishing licenses available.
Hope this helps,
Mark