cedar is very very porus. Paint soaks in and penetrates pretty deep.
You cannot pressure wash cedar,because to get any paint off, you have to have too much pressure for the soft wood.
Chemical removers would be out of budget reach. Take too much and too hard.
Go to Sherwin Williams and talk to a "knowledgable" paint person about using Woodscapes. This is a paint/stain that is for just this thing. You could get a cedar colored paint/stain that would and could be applied over this >40 year old paint and make it look like cedar.
This is what I would do.
Now, you need to spray paint this on, especially since its cedar. Rolling or brushing is too difficult.