Constructing the cab
After making the Fleetmaster part that I needed, and having cast a bunch of wheels, I started working on the cab in earnest.
I just have to say that the cab is one of the most awesome design jobs that I have ever seen. Here are some concept sketches from Weta Workshop's Artstation page:
Here is the final version from the big screen:
Taking the Fleetmaster from before, I cut out the windows and amputated the front half, then started adding it all together:
At this point, the silhouette is generally there. I still need to add the cow pusher, the hydraulic arms, the exhaust pipes, tanks and other greeblies.