I don't have a lot to touch up so i wasn't planning on sealing at all, just touch up a handful of small worn areas with paint, that's all. I'll look further into it before I do anything.
With a similar problem, just small areas with a bit of touchup to do, I tried this on my Gorgar using acrylic paints. Good range of colours at art shops and cheap - come in tubes about $4 each. I found it easy-ish to match colour, but a chunk of yellow did dry darker. In busy areas of the playfiled it was pretty easy to match and have it blend in. I put some pics in a resto thread which I'll get back to one day. Like you I hoped to get away with no sealing - big mistake as when I polished all the paint lifted - this upset me somewhat!
I think I might try again with enamel as it should be tougher - I didn't really want to either coat it or put mylar on top, but maybe you need to? People tell me the tiny little tins of paint we used to paint models with - about 20c diameter and 25mm high are enamel - so I plan to try these - probably in a black area first and then try waxing it.
