Here's a list of places you can buy black puddings at "proper" British establishments:
Clarkson Scottish Bakery 1715 Lakeshore Road West, Mississauga ON L5J 1J4
Ronald Orr & Sons Family Butchers Trafalgar Square, Brentwood Bay (near Victoria, BC) - Nice bagpipe music on their website
Maison Bramble House 17Valois Bay Pointe-Claire QC H9R 4B4
Black Pudding Imports Unit A 20243 62 Avenue Langley BC V3A 5E6 - Obviously this is the one you mentioned, Mike.
The Shamrock and Thistle Bakery 261 Queen Street Port Perry, Ontario L9L-1B9
The White Heather Bakery 109 Dundas St. East. Whitby, Ontario.
But & Ben Scottish Butchers & Bakery 1601 Ellesmere @ McCowan Scarborough, Ont
Brittania Pies, Industrial Avenue, Penticton BC
The Celtic Treasure Chest 5639 Dunbar Street Vancouver BC V6N IW5
The Celtic Treasure Chest 1534 Foster Street White Rock BC V4B 3X8
Opie's Meats. Concession Road Hamilton Ontario.
Rising Dough Scottish Bakers Main Street Preston Ontario
Peter Black, Butchers in Park Royal, West Vancouver, BC
Cameron's Meats, 12729 50th Street, Edmonton, Alberta
Tartan Bake Shop 4726 Montrose Road Niagara Ontario
Old Country Scottish Bakery 1935 Drew Rd Unit 17 Mississauga, Ontario
British Shop & Tearooms Main Street Port Hope Ontario
But & Ben Whites Road Pickering, Ontario
Mortimer's Fine Foods 5341 John Lucas Drive, Burlington, Ontario
Eagles Nest, Highway 21, Bayfield, Ontario
Orr & Sons 6-7103 West Saanich Rd., Victoria B.C. - Actually, this is a duplicate of the Ronald Orr entry for Brentwood Bay, above.
Muir's Scottish Bakery 6 Main St., S Maxville, Ontario
Crawford Scottish Butcher 7-6893 Oakwood Dr Niagara Falls Ontario
McEwan's 9200 Elbow Drive, Calgary Alberta