Gary Brown has made four liveries for the Precious Metal racer, covering many years of the airplane's ownership history. These are true works of art, so check it out. Note that there is no livery switching here - each livery is a different model name.
The airplane puts out a lot of thrust at low speed, and this is probably due to a lack of propeller inflow modeling. I'll take a look at inflow, and maybe the JSBSim propeller code can be updated.