Rigging a Cherokee 6-300

My maintenance shop rigged my control surfaces, at my request. The
plane 'seemed' to have been flying in a bank, despite having the AI
centered and DG on the same track.

They found that the flaps were the biggest culprits and adjusted them
accordingly.

When I flew it and took it up to cruise, the plane flew straight
without that 'banking' feeling. But, my rudder trim continues to be
pretty far right. With the rudder trim indicator in the middle, I
have to apply a lot of right rudder. Is this normal, or should I get
it to the point that I can have the rudder trim centered. On the
ground with the front wheel straight and the rudder trim in neutral,
the rudder is dead center, too.