For the wood grain I did a simple makeshift technique. I took a cheap craft paint type brush and dabbed it into some light brown paint. Brushed the access paint off onto a piece of paper towel. Then dabbed the tip of the brush on the paper towel until the bristles started to separate. Lastly I did some light brush strokes in different directions onto the body in what I felt was believable wood grain pattern. Hope this helps. If not let me know and I'll try to explain it better.
like most of your projects I've seen here, this one is really great. I like all the little details, your wood grain effects and your engine compartment is absolutely killer. You have some really great skills that apply to many genres of modeling.
If you ever feel like publishing your work, I know a magazine that would love to have any of your projects. I think all they would require is that your photos be on a solid color, less busy looking background. Just send me an email sometime if that is something you think you are interested in doing.