I do remember those slant nose E's. They were usually leading the Silver Star that I road to college and back (Raleigh and Jacksonville) in the late '60's. Seemed to always be aligned elephant style with two or thee E's. They were Seaboard's light green, shortly after the union of SAL and ACL (I believe).
And they capable of speeds at 100 mph (if geared right, and the E's pulling the Silver Star were)