The 9200 IC is one of two cars in the series that can be found with all three types of door guides. The other is the 9206 Great Northern. The remaining first issue 9200s were discontinued before the molded bottom guide was introduced.
An odd feature of early 9200s is a partially complete row of rivets just to the right of the door on both sides. It was the last bit of rivet detail left from the 6464s and for some reason Lionel left it on for a brief time in early 1970. Reportedly some 9200 ICs have this rivet row, but in 30 years of searching I’ve never found one. However, every 9203 Union Pacific I’ve ever seen (at least 50) has it. This is strong evidence that the 9203 was actually the first 9200 produced.
9200s are like a rolling study of the early MPC assembly line. They’re a great subject for the variation fan.