Oh my god!!!
I've just been looking at this build and what a brilliant job!
I too have recently bought a Springer hull from Models by Design at the recent model boat show in Ellesmere port, and I was thinking about making it into a Scale working tug.
I know it's not following "The springer rule book" concerning motor or prop size but I wanted to make it quite powerful.
I'm a complete newby to model boating so everything is a learning curve.
Your build has given me some inspiration as to what a good pusher tug looks like.
Keep up the good work!