Soldering would be the one thing I'd be concerned about in a pinball machine. Lead is fine if you don't disturb it by drilling, filing, or sanding, etc.. The other thing that is mentioned above is sanding the paint on a cabinet.
I soldered in my old job off and on for 30 years. If you do it safely you're fine. They actually stocked shaving cream in the supply room to apply to the lead before drilling or filing.
Use proper ventilation when soldering or sanding lead-based paint. Wash hands when done. Those are the main things to remember.
Remember, lead is safe as long as you minimize breathing in the fumes and wash your hands before eating after handling the lead.
You know those fisherman who sit next to a butchering kettle on the fire and heat up lead to make sinkers and weights for fishing? If they did that every day and breathed in those fumes that wouldn't be good.