To make a long story short, Corteco was obviously bought out by ROL. ROL had some cash flow problems, and sold out to another Mexican company, who will apparently and eventually produce the Corteco type gaskets out of Mexico. How long this will take, who knows. You may get some White Seal gaskets, or you may not. They still have mixed inventories between Dallas and Florida warehouses, as well as in Canada.So ROL wasnt really discontinued per say, but many many changes have happened. They do have some gaskets, just not sure WHICH ones. The part number you are quoting is a ROL #. The numbers havent changed from the old ROL numberinmg system.

All that said, how much compression you running? You might want to use the marine Fel Pros. They still have a 300 series stainless fire ring material with a stainless core material sandwiched in the gaslet, but they do not have a wire ring in the combustion area under the core ring. That wont be a big issue unless you have high compression.