Steering coupler..how do I get the thing back together ?

Really ?
Tell me more Rusty.

Somethin like this:

Summit RacingĀ® Steering Joints SUM-760667

Now I'm not certain that's the right one, so don't jump on it until somebody here verifies it. It's 3/4 double D on one side and 3/4 36 spline on the other. I cannot remember if that's right or not, so just use it as an example.