Thank you for the replies. The one in the car has a loose terminal but still functional, I am going to secure it but wanted to have one as a back-up just in case. For my C-Body I made my own using bakelite, machined the slots in and used the original resistor which was in good condition (the original bakelite body was cracked). If necessary I can make one, I was just looking for an easier route and have a back-up on hand. Thanks.

Still, I would like to know what the "U" stands for behind the part number on one of them that I found.