Paint job or vinyl top. What would you do first?

You'll also have to do something with the seam where the roof connects to the C plliar. Painted cars were leaded in, vinyl top cars were only caulked. Caulking doesn't keep the water(rust) out like lead.

DON'T PAINT AND THEN DO ROOF, THE ROOF WILL NEED WORK ALMOST 99% OF THE TIME. YOU MAY BE SURPRISED TO FIND OUT YOU'LL NEED TO REPLACE IT. CHECK INSIDE AND OUT. YOU DON'T WANT TO PAINT THEN FIND OUT YOU NEED TO MAKE REPAIRS. HOPE YOUR LUCKY!

Where is the option of leaving the top off? It's a rust trap keep it off

I would paint the entire car first and then reinstall a new top over a painted, not primered, roof. If the car is a weekend warrior that stays dry then I don't think having a vinyl top is anything to worry about. If your daily driving it and it sits outside with 4" of snow on it half the year then leave it off.

I found zero rust under my original 1970 top, even the window channels were spotless. After seeing photos of heavily rusty roofs under vinyl top cars I know I lucked out big time!

Paint roof, blend into tops of qtrs, dutchman, fenders, etc.

Install vinyl top, front and rear glass and moldings.

Mask top of car, any moldings, sand and prep around edges.

Paint rest of car.

Remove masking,

This way lessens chance of damage of working around a freshly painted car.