The problem is my supplier does not carry sitter cones. I always set the cones up the same way and is the # stamp as a guide to place the cone but still find there is small changes to the witness cones between firings .
I can pick them up for you and put them in the mail if it helps, I'm in BC too. PM me what cones you need and your mailing address if you want some.
(prices from where I buy mine are Small cones (box of 50).....$10.90 Small cones, each.................$0.44)