Isopropyl is fine, just expensive to use for general cleaning. Meths is cheap and handy to come by.
Both will be fine on the pF;s you are talking about. I never use anything but meths no matter what era the machine is from - dissolves dirt and grease like a charm.
On 50's and 60's games if you use Magic Eraser then you have to be careful - they arent sealed the same as later pins. The meths is fine on them, but the ME can start to rub the paint away
