I actually made quiet an effort building this alternate. Including building some prototypes like this one:
These prototypes were then disassembled and I started all over again, remembering the solutions that had already turned out good, but trying new ones where I wasn't satisfied, until I came up with the final model.
It has a rear hatch to access some cargo space:
Using a cone part on an axle was the best solution I found to achieve a spinning main rotor with the given parts. A cross section view shows the mounting of the main rotor:
Nice to see another alternative from you. Some very creative ideas here! I'm just not too fond on the big wheels here, because I like models that look realistic and in this case the wheels are out of proportion and distract too much.