Found during my shed clear out, these 3 Bahco 072 10" adjustable all seem to have a additional serial number on the end of the handle near the hanging hole. I am correct in thinking this is a kind of sub serial or version number. I have studied them and there seems to be minor differences between them all.

Hello, rustyric. Maybe a date code? Regards, Lou

Rustyric, those are forging die numbers.
See for instance: https://www.picuki.com/media/1550243865151105515

Regards
Henri

Thank you for your answer

Thanks Henri.   I also appreciate the extra info.   Hope you're doing ok there.   

Hope you all doing well in the US. I am still OK in the Netherlands.

Regards,
Henri