Morning Sun Books's "Color Guide to Milwaukee Passenger and Freight Equipment, Vol 1", by Niswonger and Strauss, has pictures of both Lake Kapowsin and Lake Oconomowoc in UP colors. The captionfor Lake Kapowsin says that they are part of a ten-car order built by Pullman in 1948-49
Lake Kapowsin, #10, is on page 54, with no photo date given. However, the caption notes that it was painted in UP colors on November 7, 1956. With the vestibule on the left end, it has "10 PULLMAN" next to the vestibule door, and "PULLMAN 10" at the opposite end.
Lake Oconomowoc, photographed in 1972, with the vestibule on the right end, has "SLEEPER #" next to the door, and "# SLEEPER" at the left end. I can't read the number in the picture.
I don't have a picture of both sides of a single car, but would think that both sides should be the same!