Charger

I am really like your build, one thing that bothers me though.
Please remove all the red spot-putty off the roof of the car and any where else you have put any of it.
Spot putty is just thick primer and keeps shrinking, it will continue to shrink after you paint the car, just giving you a heads up so you dont have to re-do the paint in the future.
To fill minor imprefections / pitting, just use reqular bondo.

I know what you mean when you mention the shrinkage. I've seen a bunch of cars that have shown low/high spots or sand scratches months after they were completed that didn't when they were fresh. But it's really a matter of giving the materials you're working with the proper amount of time to fully cure. Once you've done that and put a good sealer over it, you should be fine. I first started doing auto body work in the mid seventies. And most of the time I did it as a hobby rather than for a job. The only issues I ever saw were on the jobs that were rushed. That's one nice thing about doing it as a hobby. - Usually you're not in as big of a hurry to get it out the door. I always wondered how those cars that you see on television that are restored in a week look after a few months. I imagine a lot of them have got to show flaws.