This is a nice tree. The problem appears to be at the root base, where if the tree were replanted at an angle appropriate for the root system, the major trunk would be crooked, and the minor trunk would be dead straight.
I see that the planting angle you have chosen is appropriate for the main trunk, but it still leaves this conflict at the roots.
How about using a piece of rebar to straighten the main trunk relative to the roots? It would need to be left in place for a long time, but then the main trunk would be straight and the minor trunk could be tilted off to one side, something like what is shown in the virtual below.
