Another option would be to get a poly-choke rib. They are attached with adhesive and you can order the rib for under $150 and mount it yourself. I believe Poly-choke still ships to Canada. The Poly-choke rib for the Winchester Model 12 is about the same height as the solid ribs on Winchester Model 12's but is not nearly as tall as the Simmons ribs or the ribs on the Model 12 Y series guns. I have installed the Poly-choke rib on three of my Model 12's and have been quite pleased. I was a little reluctant at first since the rib was fixed to the barrel with an adhesive; however, in the seven years since I installed them, they have not worked loose. If they do begin to let go, you can use a wire to strip them off and re-install. If you would like to see a photo of one on a Model 12, check out the Gun Dealer web site. There is Model 12 with a poly-choke and after market rib for sale in the used gun section. It is one of my Model 12's that I traded in on a Citori.