I dont have a picture of the exact coupler thats in the car but I have a few pictures that give a good idea of how it looks.
The coupler mates a larger male spline to a smaller male spline. It looks like this.
and mates a shaft like this.
It is about this side and made of heat treated steel.
To get this custom made will cost about $300. If you have parts of the female splines then to couple and align them it is a bit less. I paid about $150 for that.