Lionel also offered additional milk cars as add ons. I do not believe they were official CCII CLub offerings. I do know they were offered in the 2002 to 2003 time.
They are car numbers 6-17349, 6-17372 and6-17373. The SRP was between $59.99 and $69.00. Ebay has the the 6-17349, ne for $50.00 and I found the other 2 range in price from $54.00 to $89.99 pls shipping. They are getting hard to find.