Spraying a flat clear coat over oil washes/filters

I'm weathering a 1/32 scale P-47, and after post-shading and an acrylic gloss coat I've applied ink to the panel lines, an oil wash, and used artist oils to apply other details and highlights.  I now want to apply a clear flat coat before applying additional details with pastels.  Do I need to wait for the oils to completely dry before spraying the flat clear coat?  I know the artist oils take a long time to dry but I'm not exactly sure how long.  Also, is there a preferred type of clear coat to spray over oil paints?  My preference is Pollyscale Clear Flat, but I've also used Testors Dullcote on occasion.  Any advice would be appreciated.

Tom