Yes, I recall seeing those GM&O E7's hauling Saint Louis - Chicago trains past Roosevelt Road in the early Amtrak years. I seem to recall that Amtrak ran the trains through to Milwaukee, making Chicago an intermediate station. If I am correct in this, that means the GM&O E7's were operated into Milwaukee at that time. Somebody correct me if I'm not remembering this correctly.
E7's were operated by several roads up until Amtrak Day (or almost), but the GM&O units are the only ones to operate in Amtrak service after that, as far as I know. I don't know whether any might have been in commuter service anywhere after Amtrak Day.