Dad,
The arms are for left steer, combo arm on the left with a single tie rod locating point, steering arm on the right, with two tie rod locating points, one the same distance from the kingpin as the left arm, one about an inch closer. I've been told via IM that the using the closer mounting point on the right does generate toe-out (and therefore "ackerman effect") when steering to the right as it says on the screenshot from Dave Steele's page and can help to tighten the car up on corner exit. Nothing to do with which side the pitman arm is on. Lately Floyd has been difficult to get on the phone so I thought I'd ask here, and I've gotten some very informative answers.
CT, your Dad's Doemelt may have the pitman arm on the right but I've seen plenty, mine included, with the pitman arm on the left. But again, pitman arm location has nothing to do with this question.