Mike -
yes, I have a sense that it's not the trickiest build out there. I haven't yet built an engine (only a boiler) so plan to start really simple, i.e. with a basic single-acting oscillator. However, I have noticed that in general people's skills develop quickly once they start, and that each of a builder's engine's tends to be markedly more sophisticated than the one before it. That's an exciting process!
gary