The green variation of these 60 series cars was one year only (1916) if you believe everything you read, most likely first used by Ives in 1915, they continued to use them in some sets at least until the frames were used up. The baggage above doesn't have a door and looks like it never did.

This is a No. 60 but IVES used a the body from a No. 550, four wheel car. This is something that you will find right up until 1930. You will also see examples of 60 series cars on four wheel frames.

The first use of the CHAIR CAR lettering for the 61. The obvious difference in this car is the simulated steel sided cars as opposed to the wood sided versions used in the Harvard / Yale series. These cars still have T trucks, always come with automatic couplers and embossed frames.

Unusual to find these red cars with T Trucks. We have to assume this car is circa 1921.

The new steel sided parlor car, matched the above two 60 series cars in all details. The example below has a flat frame.