I did my '40 with Steele seal....installed easily. Steele advised type of cement to use on the butt joint - worked great. Seal is soft and pliable against metal. Only issue I have is a slight leak on the upper right corner. I think this is more an issue of not being able to pull the frame in tight with the crank mechanism. I have seen a truck where the guy installed " cam -type " levers on the inside post which seemed to work very well - he used stainless steel boat hardware which was good quality.
