Hi,
Here is a copy of my drawing location index for those who would like it. The
BOLD lettering below should answer your question. Some Class 70 became C17 and some became C19.
I hope some find this useful. I have tried to list all the NG classes and list them and their cross references and known published plans.
Please take this as a starting point. I am sure I have errors.
Class 25 2-4-0 - NG&SLG 2006
Class 35 2-6-0 - NG&SLG 2006 and 1989
Class 37 4-4-0
Class 38 4-4-0 - Baldwin erecting card 74
Class 39 0-6-0T
Class 40 2-6-0 - Baldwin erecting card 95
Class 42 4-4-0 - MR 1944
Class 42 1/2 4-4-0
Class 45 2-6-0
Class 45 1/2 4-6-0
*Class 47 4-6-0 - see T12
Class 48 0-6-0T - Fine Lines May 1974
Class 56 2-8-0 - "Rainbow Route"
*Class 60 2-8-0 - "Rainbow Route" - also see C16
*Class 70 2-8-0 - see C17
Class 72 2-8-0 - see C18
Class 74 2-8-0 - see C19
Class 93 2-8-0 - see C21
Class 112 2-8-0 - see C25
Class 125 2-8-2 - see K27
Class 140 2-8-2 - see K28
T12 - MR July 1948
C16 - RMC 1956 - NG&SLG in 2004 & 2005 - "Steam Locomotive Plan Manual"
C17 - not yet located
C18 - "Colorado Rail Annual" about F&CC p166 and NG&SLG 1985
C19 - "Steam Locomotive Plan Manual"
C21 - not yet located
C25 - NG&SLG 1988
K27 - MR 1971
K28 - Model Railroader Cyclopedia - Baby Grande Balsam Shops
K36 - Baby Grande Balsam Shops - CAD DXF online
K37 - MR 1979 - NG&SLG 1997
DM (SV 101/D&RGW 50) - NMRA Bulletin 1972
OK here's the bit. The D&RGW classification system used after 1924 usually gets shortened a bit. The full designation is actually {letter}-{TE}-{wt}[1] for ex: T-12-47
so under this system we have:
C-17-70 (300-304, RGS 42)
C-17-71 (306)
C-18-72 (315-320)
C-19-70 (340-349, RGS 40, 41)
[data from D&RGW Folio #7 (CRRM reprint)]
Now at some point ISTR remarking that after all the rebuilding it would have made more sense for the C-19's to be 74 at the end *but* AFAIK they never were.
Pre 1924 the Classification system just ran on the engine wt, with an S or N appended sometimes to indicate gauge. So under this we had:
Class 70 (400-411, 417-422) [became C-19, C-17]
Class 00 (427-432) [became 317-319, 360,361,375]!?!
[from reprint of 3rd Div tt #100, 3/28/1920]
or
Class 70 (400,401,403-408,410,411, RGS 40,41 417-419,421,422, RGS 42)
Class 72 (424-429) [became 320, 315-319]
Class 93 (430,431) [became 360,361]
Class 112 (432) [became 375]
and
Class 71 (554,555) [became 305,306]
[Official Roster #11, 1923 (CRRM reprint)]
Doug vV
