It doesn't appear on maps, anywhere.  Not on my Rand-McNally, not on my online references, including a reasonably well maintained official cities site.  From the folks the boy talked to (and rest assured it was just two), it's called Jimtown, but there was some mention of Jamestown.  But the sign says Jimtown, so that wins, in my mind.

Nothing says "classy" like some duct tape hanging from your sign.	The Jimtown High School shared a campus with the junior high and elementary schools, of course.	This was once the grocery store, but has since closed as Jimtown melted into a part of Elkhart.
At this hour, it's tough to see, but the pizza place is apparently still successfully doing business.