Utah Belt number scheme?

[Noah Hofrichter]

I happen to own the MR July 1987 issue, and on the "prototype" (this is the fake history) they are Road nos. 1500-1514
There is only one model as of 1987, and it was numbered 1503. There is a really good photo of it on page 57 of the MR issue, but I can't figure out how to get it in here.

Otherwise, it's like this:

S-W1 1-5
S-2 10-14
VO 1000 20-24
NW2 50-59
FT 700-714
F7B 800-874
F7A 900-974
SW1200 1200-1239
MP15AC 1500-1514
GP9 1800-1839
SD9 1850-1877
GP38-2 2000-2041
SD35 2550-2584
GP40-2 3000-3015
SD40 3050-3087
SD40-2 3088-3146
SD50 3550-3569
SD45 3650-3673
Hope this helps, Noah[:p][:)][:p][:D][:p]

[Anonymous]

The July 87 issue has a roster(as you said). I have it and will look for it. If I find it (I have tons of MR's) I'll tell you right away.

[Anonymous]

Hi, I'm painting a MP15AC in Utah Belt colors but don't know what road number to put on it? December issue of MR has a MP15AC lurking in the far corner of one photo but if it wasn't for the text it would have been hard to tell, impossible to make out the number.

Expanding the question I wonder how does the Utah Belt numbering system look like?
This is what (I think) I know so far:
4-axle units have numbers in range **00-**49
6-axle units have numbers in range **50-**99

F7 900-949
SW1200 1200-1249
MP15AC ??00-??49
GP9 1800-1849
SD9 1850-1899
GP38 2000-2049
SD35 2550-2599
SD40-2 3050-3099
GP50 3500-3549
SD50 3550-3599
SD45 3650-3699
GP60 3800-3849
SD60M 3850-3899
SD70M 4050-4099

Above info is from MR November 1990 and December 2003.

Anyone that can shed some light on this?
I think the following issues might shead some light but I don't have access:
MR July 1987, February 1998 and GMR 1997

Regards O