There are several companies that sell flexible ratchet and screwdriver extensions that might work in your application depending upon how the gear box and motor terminate the power seat motor cable. I've included a typical URL below. Kajtec1 has mentioned using junk yard parts which you've already noted. This may be a case where necessity is the mother of invention unless you can find a Chinese clone replacement part before tariffs and IP problems get in the way :0).
https://www.amazon.com/HORUSDY-3-Pi...76&sr=8-7&keywords=flexible+ratchet+extension
https://www.amazon.com/HORUSDY-3-Pi...76&sr=8-7&keywords=flexible+ratchet+extension