Filling BR740A Bale density system

Can someone help me with the basic setup to refill a BR740A bale density system.  I've found a coupler 73163493 online but I hope it can be had for less than $71 or so.

 

I know close to nothing about these balers and am trying to help the neighbor put a new to him baler into service this year.  The neighbor is not real good with the web.

 

I'm figuring some type of hydraulic line needs to be put together to connect the tractor remotes to the baler along with a coupler to attach to the tee.  All the different types of hydraulic fittings are greek to me too.

 

Thanks

 

 

Filling BR740A Bale density system