In order to protect against part obsolescence, an industry standard part was chosen.   In the event that the part in the BOM becomes obsolete, it can be easily replaced with a similar part.   Of course, the part in the BOM to begin with is the most cost effective part made by a reputable electronics part manufacturer.
Instead of getting a mechanical sample of the customer's motor assembly, they provided me with a 3D model of the PCB size and shape that they needed.   I was able to import the 3D step model into my design software, and automatically re-shape the PCB to their exact specifications.