Jim
Pat Walker probably sold more (if you can use 'more' to describe what was probably only a handful) than any other dealer at the time, but I suspect they were largely destined for the UK.
The story here goes that the SA80's that went to Canada were exported by the manufacturer, at the time depending on the exact date that would probably have been Royal Ordnance Nottingham, in a bid for export sales.
Having said that, when the 1988 semi auto firearms ban (post Hungerford) was looming, Pat Walker certainly offered a service where he would handle potentially banned semi autos and export them for owners (see attached).