First thing we need to determine is the type of paint that was used to paint the deck. Was it done in an oven, has it fully cured?
If it's fully cured, yes, you can rub the runs out, but it depends where they are and if you can access them while using a sanding block, with possibly some 600 wet over the top.
If the deck is dry, which i'm sure it is, give the whole thing a wet rub with some 800 before you apply any clear or silver over the letters. The idea is you want to get the shine off the existing coat so any new coats can stick to it. Generally you apply clear while you're painting the color and you would put that on after the final coat of color flashes off. Yes, clear is available in pressure packs and it comes in enamel, eg like the "export" brand of paint at about $3 per can, or it also comes in acrylic in the "motorspray" or "septone" brand available from supercheap. Personally i prefer the enamel as it gives a much glossier finish, but requires more light coats with about a 5 minute flash time between coats, dependant on temperature and humidity.
