FYI-an extended cab was available in the '64-'66 Chevy C10 models. I believe one of the Motor Coach fabricators performed this customization back in the day. There are a few '60-'66 Chevy bolters that can shed some more light on this subject.
I wish my body skills were as keen as your photoshop skills. I would like to convert one of my '64-'66 Chevy trucks to an extended cab. Good luck with your conversion. It looks really cool.
