The Flying Lady

For many years, mascots were the very embodiment of a car manufacturer. In those days, all one had to do was see that mascot and you would instantly know the kind of car it was. Plymouth used a few different mascots over the years, the most recognizable being the sailing ship. However, the most stunning has to be the "Flying Lady" or "Flying Mermaid" of 1931-1932. There is a great article on it here at Allpar:

Beauty is important in all things, however in automotive restoration we have the added challenge of making sure that this artwork can get down the road! Follow along as I fix something that most people will never see.

1931 Plymouth PA Rumble Seat Roadster

That beautiful young lass also serves another function, however. She is the radiator cap!

My job is to make these cars go as well as they look. When I removed her from the car, I wasn't pleased with how the previous shop had attached the seals to the cap after she was re-chromed

I use the term "seals" loosely, as they appeared to be hand cut from cork and tar paper. It was all weakly held together with rusty bolt. 

This all fell apart when I removed the cap.

I measured the opening of the radiator neck and compared that with some good used caps I had around.

Donor cap cut apart and cleaned up.

Mocking up for the proper depth and order to sit properly in the radiator opening.

I drilled a washer and cut the center with a square key to lock everything together so it won't move when you turn the cap.

Seals and spacers installed and clocked straight. Copper washer in the center to seal the bolt. 
This is a non-pressurized cooling system, so the cap just has to keep the water in. 

This Flying Lady now functions as beautifully as she looks!