'66 pickup vin code locations?

[kmojo]

Hello,

I'm new to chevy trucks having just purchased a '66 lwb Fleetside the other day. My problem is that I can't find a vin number. The one place I know to look, on the door frame, just has rivet holes where the tag used to be. Where else can I look?? The vin on the title decodes as a 3/4 ton but I'm not sure it is. What is an easy difference to spot between a 1/2 ton and 3/4 ton? Sorry for these naive questions!!

Thanks,
Klaus