Minor update, after starting with what seemed like a million pieces of tyre tread, the wheels are all done, ready to paint. I'm still waiting for some paint I ordered to arrive.
After adding all the treads, including my added details to the hubs, total number of parts used so far is 3128.
It's going to be nice to not have to look at or think about tyre treads for a while. Up next I'm either going to start on the chassis, or the steering and suspension parts.