i want to buy this g400 2nd hand but i just want to clear something up

on this model in the head section it says 'gibson', but i have seen other models have 'sg' such as the following pics

the one i saw had a serial number on the top of the head back side and thats all... can someone let me know if this is correct, thanks
I'm no expert but the pickup selector looks abnormaly close to the volume pot
well i found another pic that looks the same as the one i want to get

maybe it was the year it was built and there are slight variations