This wheel is listed on ebay as a 17" Cobra spare tire and although it looks like steel, they say it's aluminum. There are a few on there. The particular listing this one came from says it also fits '05-06 Ford Escape which does happen to have a 4.5" bolt pattern. Maybe from the hybrid version to cut down weight. Hard to tell the offset from the pictures they have. Other Ford Escape spares look like they have too much offset like your Jeep wheel.

http://www.ebay.com/itm/05-06-Ford-Escape-99-04-Mustang-GT-Cobra-SPARE-TIRE-/110792746506

7181024-cobra_spare.jpg (110 downloads)