Thanks!
Lots more to come for the Stearman; planned improvements are the addition of the engine bay interior, wheel chocks, tail-wheel lock and handle, further detailing and modeling improvements ( such as the wing-tip extra polygons and rudder tidy-up mentioned already ), texture enhancements in the cockpit, and it looks like enough people would like the engine and wheel fairings to make a second model version worthwhile. No extra engine types or sounds though, that would take too much extra time and money.
Will include all the above in a second update, maybe in a month or so, to allow for any further suggestions by the community to filter through.