All you need to be street legal is you or someone to mount a red lens and a light that functions when the brakes are applied, right?
If you also want it purty, that’s your choice and a different matter.
The problem with the ford tail light is that it’s a very complicated device, with a very complicated wiring connection and function. It feeds back to the computer system with electronics built into the tail light. If it fills with water, you’re in deep doo-doo.
I prefer to avoid such vehicles.