Marks gave you good advice there Kelvin, you'll need to get that paint off (filler??) completely, get it sanded right down to the bare wood. As he says you'll need to use a filler, I used 'Tamiya'' filler but that could be expensive as it comes in small tubes,(it still goes a ling way, it's quick drying and easy to work with) car stuff may indeed be the way and it should be cheaper. Just remember the golden rule, apply it thinly, once it's dry, sand it down. Do this as many times as necessary unti it starts to get smoother and smoother. Once you've got the real roughness off it,and it's starting to look good, smooth, just like metal!, there is a car primer that also has filler incorporated into the spray can, use this lightly to fill up small gaps/cracks that are still around. Polyfilla also do stuff in a yellow tube, called 'finishing' off, this really smooths it down before painting, and also remember for best results with the undercoating and final painting is to use spray cans, or if you have an air brush, use that. Always make light passes, let it dry, do another. If you still have cracks and unevenness, sand it, just keep doing it Kelvin, it'll come out far better than you ever expected, and you may even praise yourself, there is no hurry, you are not in a race, time my friend is on your side...Dave