Has it become industry practice to rely on the "frustrated user corrections" method instead of "proofing" the product before release? Sure somethings will slip through but important items like rolling stock should be checked for errors.
Traced the fault to the Default "tankcar_Digits.bin" in the Default\Wagon\textures Folder.
Entry at the very top said "cement digits" instead of "tankcar_Digits" as is called for in the Default\Wagon\tank_car.bin entry line:
<BlueprintID d:type="cDeltaString">RailVehicles\Freight\TankCar\Default\Wagon\textures\tankcar_Digits.xml</BlueprintID>
I will be submitting a rwp file with just the corrected "tankcar_Digits.bin" in it named "HiLn BlkTnk Car Num Fix".
Or you can locate the file at Assets\VNHRR\HiLine\RailVehicles\Freight\TankCar\Default\Wagon\textures\tankcar_Digits.bin and open it up and correct the entry yourself.