Taylor,
I really wish the drawings were arranged by Build Number, but they used the Sierial Numbers instead.
Such as GLR #40 is Build Number 53777, but its Sieral No. is 10-26E-416
10 = Number of wheels on locomotive
26 = (16" bore - 3") * 2 = 26 (don't ask me why Baldwin did it this way.)
E = 8 drive wheels (B = 2 Drivers, C = 4 Drivers, D = 6 Drivers)
416 = 416th engine of the 10-26E Class
So #40 is the 416th engine built of the 10-26E class of locomotive regardless of track gauge, exports, fuel, weight, etc.
If you can give me (Who Built For) - (Date Built) - and (Class) for each of those engines I can look through a Card Index and should be able find out their full serial numbers.
Such as SVRY #3 was built for the Nevada-California-Oregon, in 1888, Class 10-26E
As to the #250 & #251, I'm pretty sure (as in not 100% sure) that their erecting side elevation and crossection drawings still exist. I'm not sure if they're in the DeGolyer though.
See you soon,
Curtis F.