+1 on the above. I used to design wiring harnesses for heavy truck and off-highway equipment. A connector is available, but finding an oddball connector like that, new, in a consumer retail place, is very difficult (for OEMs, however, it's a completely different story, esp. if you are buying in high volumes).
If you can identify its use on any piece of equipment (from a car or truck to industrial air compressor), you may be able to go into the parts department of the equipment maker or car dealer and get a replacement connector, typically sold in a pigtail configuration (connector shell, terminals installed, with about 6" of wire for splicing into the existing harness) for service repairs.
As stated above, searching boneyards is the best bet. Final long-shot option is to obtain a "sample" (wink wink) part if you know somebody in the OEM world that has connections with the suppliers (sorry, I'm not in that business any longer)!