Could someone tell me if they make a smaller jet ejector than the cast iron one everyone sells. Its made to fit on the front of a pump or go inside the well casing. Well this one wont fit inside my old well casing. I'm assuming too much rust on the inside of casing. The original jet was solid brass and smaller than the generic jets. I'm Wondering if they still make the brass type jet, or something small for a deep well. thanks