reworking a fully restored car

In the past I've shot single stage, let it cure, wet sanded out dust, peel, whatever, I'd scuff it and shoot a urethane clear over it. Those repairs have lasted for years.
Thanks I'm getting conflicting info from all sides so my current plan is to let it cure until it warms up this weekend , then hit it with some 2500 grit and if I f it up block it down with some 600 and shoot it again in 70 degree temps . I have another can of paint plus a can of 1K acrylic clear ready to go .