I just dustless blasted my 68 Shelby convt. and epoxy primered it today. If you could keep it inside away from any high humidity you could probably leave it awhile. I waited 3 days. They used a rust inhibitor in the water they use with the media so no rust if you don’t wash that off. The dustless blasting was good, I’ve used it before and no issues. They will take off any old bondo and you can see just what you have. I had a lot of previous work and have to decide what to do next bit looked good before blasting. Oh well, old cars.