The book you referenced is Greenberg's newest edition, which is more comprehensive than his earlier editions. I do not have any Standard Gauge or 2 7/8" locos, so that edition, is of no use to me. The price was another contributing factor, as to why I didn't buy that book. Bruce Greenberg is presently working on his next edition, which will cover the 1928-1942 time frame, which is the next book that I will be getting. It isn't set for release until some time in 2020, though.
I had a chance to think about these motors, and Lionel's marketing strategy, covering different time frames. Lionel's early years, leading up to the 1930's, dealt mainly in Standard Gauges, and larger "0" scale. The majority of the Standard locos (Electrics), used motors, very similar to the Bild-A-Loco motors, that all would have used the Drum Style Commutators, with Brush Plates that were similar in design. Lionel (along with A/F, bought out Ives, in 1929), and starting in 1930, Lionel started to produce lower cost trains, which is what we now call "027". This was mainly due to trying to survive the Depression, and to be able to sell cheaper trains, compared to their earlier sales of high end items, of the Standard Gauge. The majority of the early 1930's locos, used armatures, with the disk style commutator, but a lot of the 027 units lacked a reversing unit. It wasn't until 1933, that Lionel finally redesigned the E-unit, from the Ives original design, that would replace the earlier Pendulum style reverse units, (which were big and bulky). Using the newer style motors, with armature/commutators having the disk style, simplified the manufacturing process, which all took place in 1933-34. By 1936, Lionel moved away from the Standard Gauge trains, and relied more on the "0" & "027" gauges, to stay competitive. Prior to 1936, most of the trains were actual "Tinplate", but in 1935-36, Lionel started producing Die Cast bodies, which were better built. They were cheaper to make, and could be mass produced in larger quantities, which kept Lionel afloat, leading up to WW II.