oddities:
There were 2 SFS engines put in class 40 in 1895, see my post to Andrew below.
Class 70 c-17, c-19 advanced weirdness:
original 1881 Class 70 engines (#400-411) became class c-19 (340-349 RGS 40, 41) in 1924
2nd group of class 70's from 1887 (#417-422) became class c-17 (300-304, RGS 42) in 1924
two oddballs: ex RGW std ga engines, converted from Na Ga, converted *back* to Na ga by D&RG in 1917 (D&RG #'s 554, 555) were numbered 305, 306 and placed in class c-17 in 1924 BUT were different from the other c-17s and, I'd guess, each other!
Just to be annoyingly complete.
hank