Looked on frame inside & out, top & bottom and didn't see anything. Pretty rusted though.
Also did research on vin #'s of that era, interesting stuff. After spending hours & hours comparing this frame with images on different sites i can tell that the gas tank was most likely strapped under the cross member at the rear and brackets towards the rear on each side were supports for running boards, steering box was mounted inside with linkage passing thru the frame then down to the arm. Here's are a couple more photos maybe someone might recognize front cross member, looks like an engine mount.