Bosun,
I did it this way:
Painted the yellow, yes it is satin, allowed it to dry thoroughly. I then used Tamiya masking tape and used brown satin paint within the masked off area. Then, before the brown paint dried, I used a nit comb and a sharpened pencil rubber to drag streaks of brown paint off.
I suggest you do one panel at a time, otherwise the brown paint (or whatever you use) may dry a little, making it hard to drag off. Also, clean your nit comb/rubber between each use, just a wipe on a rag should be ok.
I then allowed it all to dry for a couple of days and sprayed over with a little satin varnish.
For the comb, I cut out a a section and then removed a couple of teeth so the grained effect wasnt symmetrical.
I also practised on some scrap first, its actually a lot easier than it might seem.
Lets see some pics when you have done it.
Ian