Prep, prep, prep. Sanding is critical. I plan to paint my truck I have tested a few panels and cannot get over what shows through, tiny scratches from the sand paper, tiny pinholes in the filler (even glazing). I am rusty. I have not done finish body and paint for many years.
I found a guy locally that does only restos on classics. Suprizingly he said he can make the truck look really nice for $1500,,,not show quality because I don't want that but very nice. I looked at some of his work and it is really impressive.
I would still like to paint it myself but it is nice to have a back up plan if I have a breakdown from sanding and blocking.