Original manufacture means the event of freshly manufacturing a locomotive or locomotive engine. The date of original manufacture is the date of final assembly; except as provided in 92.11. Where a locomotive or locomotive engine is manufactured under 92.11, the date of original manufacture is the date on which the final assembly of locomotive or locomotive engine was originally scheduled.
40 CFR § 92.2
The definitions of this section apply to this subpart. They also apply to all subparts of this part, except where noted otherwise.