You might want to cut your own using Neoprene Foam Closed Cell Sponge EPDM sheet. This material is similar to the original gasket material. 1/16″, 3/32″ and 1/8″ thicknesses are available on Ebay in smaller sheet sizes. Use the lens to make an impression on the sheet to make an outline and cut it carefully with an X-acto knife. Should be waterproof especially when compressed.