It's a combination of about 8 years worth of Chevys. It resembles from '55 up to and including '63. There's a strong hint of 63 in the door and roof panels and I must include...I can't believe I'm actually participating in this thread!
I don't see the International in it nor the Willy's. Willy's had flat fenders and panels with a rounded roof panel. I had a '55 p/u for years.