Does anyone know where I could find a manual on an airco spotwelder I have?

I want to use it to spot weld tags to my product but i do not have any idea on where to begin on using it. I have found that miller made the airco products for a while and I am sort of reaching for some information. If there is anyone out there that has some information I would appreciate it.

Airco spotwelder
code- 0694
serial# AH806061
stock- 23200070