"Pendulum car truck is designed to support the car body 14 inches above the center of gravity and secure easy riding around curves at high speed." There is a photo to go with that statement showing the truck, and it appears that the springs and stabilizers extend upward into the carbody a couple of feet, which probably explains the lack of windows over the truck centers.

The photo illustrates the Heywood-Wakefield Sleepy Hollow seat. Typical railroad coach seats were little more than padded benches, so the development of a comfortable seat was an innovation at the time. Life Magazine ran an article on February 11, 1946 about the seat , and here it is, entitled; Hooton's Chair Harvard Anthropologist measures 3,867 people for a railway seat:

The science of sitting down inched forward a bit last week. The Heywood-Wakefield Company in Gardner, Mass., biggest maker of railway coach seats, perfected one that more nearly fits the seated human body than any yet made. The company calls it the Sleepy Hollow Chair. Nearly everyone else is calling it the Hooton Chair. Reason for this name was that for months Harvard University's well-known anthropologist Earnest A. Hooton, and his staff of statisticians had been prodding and measuring 3,867 volunteers and compiling statistics to determine what U.S. travelers should have under them. His mass of results were used in making a new seat scientifically tailored to the average railroad rider. Meanwhile, experimenting with a wooden chair filled with sand on which people left the impressions of their posteriors, the Heywood-Wakefield Co. arrived at a set of conclusions which, to their dismay, were precisely the same as Dr. Hooton's. The photo captions stated: Fattest man tested in Dr. Hooton's special measuring chair was Adam Reimer, who weighed 325 pounds and measured 56 inches around the hips. Ordinary railway seat is too hard, too vertical for ample Adam Reimer. Few abnormal sizes were measured because they complicated Hooton's computations. New railway seat fits Mr. Reimer better. The deeper cushioning gives with his curves and the inclined seat distributes some of the load against the chair back.

Reprint of article here: http://streamlinermemories.info/Eastern/LifeSleepyHollow.jpg