I've been there. It is a bit out of the way, and unfortunately the museum was closed for the season. But my Dad & I stopped at the barn, the elementary school (just check in at the office, and they'll tell you where you can go), and there was a park. The barn is off the main road before you get to town, so you can stop there first. There are also a few antique stores in town, and if you mention you are looking at Disney they'll get you pointed in the right direction. You can also get a good breakfast at Susie's Place.
We did it when I helped my parents move to FL. We spent the night in Chillicothe, and then spent the next morning in Marceline, before we were on the road again.