Chevy 37 ,
Do you know if the car was taken down to the metal & built back up with this paint job thats on it?
If so I would say go with this option:

If the paint is still in good shape like you say , but just fadeing, you could water block sand with 400 grit till all the shine is gone from the paint , then seal it and spray it.
I would also reccomend PPG's Base Coat /Clear Coat in either DBU or DBC .( Very forgiving)
DBU uses a reactive reducer & it will harden & drys faster & easier to work with.
DBC uses the same reducer as the clear will use so this will help cut some cost.( you can also purchase a base hardner for this product , that makes it like DBU , but then the cost is the same as if you went DBU.
Then use DCU 2021 Clear , its a high solids 2 coat clear.

When you get closer to painting I will give ya some pointers if need be

Spray