Work in Progress - Farmall Tractor

I've been playing with this new painting depicting an old Farmall tractor.  I have a soft spot in my heart for these tractors, since Dad had one on our 120 acre dairy farm, and he's sometimes let me drive it.  Farmalls were manufactured by International Harvester, and were common on small and medium sized family operations. I painted this from a reference photo I took at the recent Walworth County fair, a place that also is nostalgic for me.

There is a local painter who often paints pictures of tractors, and I emulated her style here, with exaggerated color, simplified forms and abstracted backgrounds.  This is the acrylic layer where I work out my composition and play with color.  When the painting feels about right to me I paint over this layer with oil paint, making alterations along the way.

UPDATE - This is how the painting finally turned out, oil over acrylic.  I pushed values more, and added some magenta to the cool areas on the tractor.