The Chinese have no interest in anything that is not generic, fuel pumps, filters, etc. Anything model specific won't be of interest to them, unless it is something like those 175cc machines that are so prolific in S.E. Asia. And maybe even those won't interest them.
The only solution I see is short run prototype injection molding with unhardened aluminum tooling. This process is advertised as being cost effective for runs as short as a couple hundred parts. Of course, as Bill Clinton so famously said, it depends on the meaning of "cost effective".
The biggest hurdle I see is getting a digital file of the lens that can be used in a cnc machine to create the mold cavity. That is the part of the process I have no knowledge of. It does appear from advertising I have seen for modern dental work that there are ways of mapping a 3 dimensional object and creating another object from the map, so I guess the technology is there.
Does anyone here have any experience with 3D mapping? That would be the starting point for getting a price to make parts.