I scour the planet for blueprints, sometimes, I have to extrapolate from 3/4 views, to get the right over all relationship. The "Hermes" Tugboat had some pretty good blueprints available.
I had lost the final model for ESKA, but found a back up file on my other computer (too many hard drives). I should release this, but it would be a difficult build. I did build two of them. My son had a blast with them, so did I. It's something you would really want to build. This is built to the two seat bleprints. There is one in the download section, but it's accuracy is not so good, though it makes a great model.