Thanks for the comments re the whitewash.
I decided to try this method because of the temporary nature of it. i.e. if I got it wrong I could start again.
I built a skyraider, made a lovely job of it too, painted it in a combination of enamels and acrylics. I read somewhere you could spray laquer as a top coat prior to decals going on. Ooops big mistake. It made the paint ripple and peel.
so I had to strip it and then I lost the motivation to finish it. So its consigned to mothballs until I decide to have another go. So now I try to use what I know or trial on a disused kit.