Atlas N scale FM

Having recently purchased an Atlas N scale FM H-24-66 Trainmaster in CN, I set it out next to my Atlas RS-1’s.
Is this Trainmaster to scale?? It is only slightly longer than the RS-1’s, and does not look all that larger than any of the other N scale locos I have. Which leaves me wondering if something is out of kilter here. Anywhere I can find data to either 1) prove the Atlas FM IS to scale, 2) photos of the Trainmasters next to other locos of the time showing the size difference??? Thanks much.[;)]