ConducTTor wrote:are there multiple number combinations on the decal sheets? And if so, how many?
The TT-West decals have a primary car number... based on the prototype number series,
and a semi-random 'number jumble
', which contains the first two digits of a prototype series, followed by a bunch of extra digits.
Both car numbers (usually 9-inch...) for the car side, and 4-inch end numbers are included, and the jumble includes every digit at least once.
The modeler would combine the first two digits of the jumble with the trailing three digits of their choice. It was intended that groups of three adjacent digits could be used to reduce decal splicing, but individual digits can be used to exactly match a specific car. Obviously, the digits can also be used to change one or more digits of the primary car number...
Here is the C&O 'Progress' example.
Commercial Site: https://www.tt-west.com/tt-scale-cars