Steering shouldn't be that stiff. For one thing you shouldn hardly ever be trying to turn the steering wheel at an absolute stop. Just creep the car even as little as a few inches and it will make a big difference.

If the steering still feels heavy check your tire pressures. Running slightly higher pressures might reduce the effort.

Jack the front end up on both sides (a floor jack in the center of the crosmember works well). Spin the steering wheel from side to side. Is there still resistance? Check the oil in the steering box, and cast a suspicious eye on the ball joints. They can get mighty stiff just before they start coming apart.

Its pretty hard to find a place that will actually bother to set the alignment up properly on an old car like the 1800. They just dont want to fiddle with unbolting things and messing with shims.