Airbrushing is what I do but if brush painting is what you must do then there have been modelers who have done this as well as any airbrush. Maybe some of our very tallented modelers on this forum can tell their technique as I would like to know myself.
I don't have an airbrush (and I don't really want one either), so when thinking about it, maybe spreading it thinly around and mixing it would do? Thanks for the advice.
Thank you all for the suggestions. I have finished it now, with a few modifications (sourced from a photo) and may post photos (but don't get exited - I make a lot of promises).