60-63 has the knee knocker/wrap around windshield. 64-66 flat windshield.
Vin no.2: may be Canadian GM 1960 Panel, 6 cylinder, less than 6K GVW.
Vin no.1: may be Canadian GM 1965 stepside, 6 cylinder, B5 ?
"Given" two serial no's? By whom? What type of document were the SerNo's on? What is "their" explanation of why they gave two. Search pics of 60-66 cabs here in gallery to confirm shape. Why no vin tag on door jamb/kick panel? Was he given a title? What do you want to know? Just the year or what? Obviously if it's a panel you would know that. So if windshield is "flat" type, go with 1965 Vin/SerNo.
General commentary : If SerNo's are on anything other than a title, with no matching Cab Vin plate , those number are not worth the paper they are written on.
