I broke the heel piece on my tiger sharks, so I am looking for a new, used or half a set.
Check out evo.com http://www.evo.com/outlet/alpine-ski-bindings/marker-120-free-110mm-brake.aspx#image=24411.Color.Hardgoods_Black_Image.jpg. They are selling Marker 12 free binding which has the same toe and heel pieces as yours. I had 1200 IPT on my Gotama and last year I replaced all pieces without dismounting a plate with these bindings because my heals started falling apart after 6 seasons. Compare the screws on your existing bindings and these ones - you should have two long and two short ones on the heel and two (maybe three, mine had 3 holes but were attached with 2 screws) in the toe.