Threads a bit old, but more info... It is the Summit 150 GPH pump, now since discontinued.
Friend has two that work fine.
Appears to be a less glamorous copy of the Aeromotive pump to us, (without the fancy color anondizing on the aluminum and no chrome on the motor casing), you may want to contact them and see if their gasket is the same. They may even be the ones who made it for Summit to put there name on it.