I obtained this set on eBay
from the estate of a retired Sacramento Northern mechanic.
The set includes
19 SN and 7 TS elevation drawings of all the diesel-electric
locomotives and revenue freight cars operated by the
SN & TS
after WWII. They are bound together in an 8x12 pamphlet
(folio) in blueprint format on heavy stock drawing paper,
1 per sheet.
A guess is that these were a maintenance field or training
guide put together by the SN engineering office. In addition
to the side and end elevations, each drawing includes
dimensions, car #'s, capacities, origin, equipment, appliances,
specifications
and years built, plus additional notes of all sorts.