If it is something like Marine Ply Jerry then it's a bit to orange on my monitor, maybe do an over brush of a light stone or buff if your using oil based paint. If not then the same colours applied as the Dry Brush method. Try a sample first though.
The base for the plywood can be a Matt Linen - Humbrol 74 for example. Then you can use a Matt Pale Yellow ( Humbrol 81 e.g.. ) and a brown colour for the wood graining. ( Humbrol 133 for instance ).
Because I don't have any of my own pictures showing the process I'm using a couple of images found via the net..
The first step is to apply the base paint for the wooden imitation....
The second step is to apply the wood graining with paints usually used by painters ( artists ). For the applying should be used a brush of quite stiff bristle. According to my experience almost the same effect can be achieved with the dry-brush technique using standard enamels/paints for modellers. Those ones for artists need a quite very long time for drying.
The third step is to airbrush very thinned brown paint or another one overall that is of the plywood colour. If the linien and the pale yellow colours were used the coat should be airbrushed with the brown paint. The trick is to apply the paint with a very thin layer in the way the graining can be visible through it. Finally the gloss dope can be airbrushed in order to get the effect of gloss varnish on the plywood.
Oil paints are the easiest and result in the best If you need a guide, just send me a pm and I'll send the steps over along with some pics
Depending on which thiner you use, you can make it set in 2 to 7 days, if you want the fast dry oil paint thiner on oil paints, or if you use the standard I use the 7 day because if you end up making a mistake or don't like the outcome, just dab a little thiner and edit it till you find the right result, even 4 days out
P.S. I nearly forgot
I have a small guide in my Nieuport 17 thread on page 2 for wood grain the same can be done for a lighter color wood, just choosing lighter color oil paints.
His Heinkel build should be bookmarked, I went back like 6 pages to find it at the time when I was looking for info. Very nice build, its like you had 7 people who were experts at each thing (engine, wood, cockpit etc) that just merged into one person scary