I have an old enameled cast iron bath tub (at least 40 yrs old) that has developed a leak at the seal underneath the tub. I was not able to actually see where the leak was being generated, but I do know it is leaking at the seal and I was able to take some pictures (please see attached pictures). In the picture I noticed what seems to be a hole or rust spot in the tub above the seal and I'm concerned I might not get away with just replacing the gasket. I also am having trouble figuring out how to actually remove the drain pipe assembly. There does not appear to be any way to remove the polished flanged sleave from the top of the tub because there seems to be no way to grab hold of it. Any advise would be greatly appreciated. I hoping not to have to replace the entire tub, but I'm nervous about what I see from the pictures I took. Maybe if I can remove the fittings I will be able to evaluate the entegrity of the tub above the seal. Thanks.