Metra Pullman (smooth-side) cars on the Milwaukee District

It's not unusual to see Pullman (smooth-side) gallery cars sitting at Western Ave. (there's four on the "dead" track right now). But this week, for the first time, I saw one running in a Milwaukee North train. Specifically, 2143 (I think - it's the one that is normally double-headed) returning the next morning as (I think) 2118 has had a Pullman next to the engine (I believe as an extra car - normally this is an 8-car train but if my count was correct, it's been nine cars the last two days). I don't recall ever seeing or hearing about the Pullman cars running anywhere except the ex-C&NW lines.

In the late 90's to early 2000's there were a few refurbished Pullmans running around the Milwaukee District. Im not sure if they were strays from the north central group of pullmans, but i definitly remember seeing them quite a bit on the Elgin trains.

I've seen them on SW service couples to a Q bilevel how often has that happened?

What line do they normally run on?

They can be seen on just about anything running on the three UP (ex-CNW) lines out of downtown. Better luck during rush hours of course...

Note that one and possibly 2 ex Rock PS gallery cars are on the 261 Polar Express.