K-36 Baldwin builders numbers.

Hi All

Does anyone have any info on the build of the k36s at Baldwin. The builders numbers don't line up with the loco numbers assigned to them by D&RG. 482 appears to have the earliest build number follow by a jump of 17 locos to 480 & 81, then a large jump of 25 locos to 483 then consecutive build numbers to 489.
I would assume that the first loco may have been a trial for the railroad to see so would be an early number.

Some interesting history in this that I would love to know more about. Does anyone have copy's of correspondence between D&RG and Baldwin? Or contracts of sale? Would be very interesting to read

Regards

Greg Pepperell