I have been painting my M5 tractors. Only managed to get one done for the painting competition but finished the others now. I also had 4 from Pithead so I show a comparison too. I like both and will use for different 155mm batteries with the Pendraken version earmarked for a later Long Tom battery. Here is a link to my blog post:
http://smww2andnapoleonic.blogspot.co.uk/2015/03/us-m5-high-speed-artillery-tractor.html (http://smww2andnapoleonic.blogspot.co.uk/2015/03/us-m5-high-speed-artillery-tractor.html)
Steve
All of the models look really good and the "how to" guide for the roof of the Pendraken model should save some heart-ache for others.
Nice looking stuff.
Great tracks!