Since I started 3d modelling and scenery design I began to understand that this is takes a very large amount of time, excpecially when a high level of quality is desired. John is among the best, in my opinion - and that level, if you don't have a team to spread the work, you easialy can measure the development time in years.
I'm very much looking forward to the P-39, patiently!
Cheers,
Mark