Replace burner seals of gas cooktop

I've got a brand new 14 year old Kitchenaid glass gas cooktop which I just installed. The seals or gasket gave a horrid rubbery smell when the cooker is used for 10 minutes or more. I dismantled the burners and have been trying to replace the seals or gaskets. Kitchenaid/Whirlpool says my unit is obselete and no longer carry the seals. Any idea what other seals I can use to replace them? The original seals are like 1/16" in thickness and 3" and 5 3/8" D and 1/2" wide. They fit in between the ingniter unit and the glass top from underneath. One appliance parts company suggested canning seals but I fear they may not withstand the heat. Any alternatives and suggestions would be greatly appreciated, thanks!   product: Kitchenaid 30"gas sealed cooktop  model #ykgct305t