Respray over new paint

I have been painting my 65 coupe peice by peice with not enought light. An now that it is complete with noticable color shades, Now I have a building to shoot it all in one shot what prep work will or could be done, like scuffing it with a scotch brite pad,degreser an cleaner an a good tack. Whats the best thing to do?  

a good scuff and good body wash, with a re spray..  

I would prefer to lightly sand with 600 or 800 grit to remove surface imperfections before the scuff/clean/tack/reshoot.