As promised, here are pics from our lunch at Poopy's, which wasn't busy at all at lunchtime. I must say, for a waitress at a tattoo and piercing parlor/ motorcycle repair shop/ roadhouse who must have seen everything, I got quite a quizzical look for whipping out the camera...
Food arrives in a bucket - I was relieved, considering the menu implied that they might serve it in bedpans

:

Very nice burger, fries are thick-cut - not my favorite type even though they showed some skin, coleslaw very good and fresh, sodas huge and frequently refilled:

Greaseless pork tenderloin in a crunchy-crumbly crust. Had to eat for quite some time before I hit bun:

Sparky opted for the lunch buffet, a real steal for kids under 10 at $4.95 (I think it's something like $7 for adults) He chose the fried chicken, which he liked and which was serviceable considering it had been held in a chafing dish. Green beans were very good old-school cafeteria style with nice hammy flavor. Mashed potatoes and cream gravy looked very good (couldn't talk him into getting some) and there were also sliced pork and sliced chicken dishes in their respective gravies that looked pretty good for what they were. He also got a slice of pie, opting for a lime meringue that was pretty good - other offerings looked a bit wilted, having been pre-cut and set out, but the cherry and rhubarb and seemed made locally if not in-house (I didn't ask.)
The cafe I wished we'd been able to check out is called the Savanna Marina Cafe, immediately inside the marina at
1 Main St
Savanna, IL 61074
Phone: 815-273-2956
Like many restaurants in town, it didn't appear to be open on weekdays. For future reference, the Savanna Chamber offers this
Dining page.