Older air toola

Hello I am wanting to get into restoring old pneumatic tools. I am starting with some old 1950s and 60s air impacts. I know you have to oil the air inlet. But ive seen videos of impacts using gear oil or grease on the mechanisms. How do I determine what these oil tools need, as I probably wouldn't be able to get a manual for them. Any pneumatic tool not just impacts but as of right now , impacts lol