back in the day when we received brand new machines into the arcade I'd say there was a good 15% chance that something convergence related was off from shipping. usually the machines that arrived from our normal distribute a few states away was ok, but anything that came from the west coast was like a 50/50 shot that something would be off.
in my personal collecting I've had 2 machines lose convergence in shipping (several more than that were fine), I think it depends A LOT on who handles the cab. Usually transport on a truck is fine since it's mostly highways and there's a cushy suspension and big inflated tires. it's the loading and unloading on those hard rubber wheels, and across 2in drops at the end of ramps or over thresholds that do them in.
new machines of this vintage shouldn't have any strips from the factory. generally what happens is the clamp on the back of the yokewiggles lose and causes the whole yoke to sag ever so slightly. it's typically more prone to this the further back the tube is angled... mirrored light gun cabs were the worst because you hit a bump and the whole weight of the yoke tries to slide that clamp down the neck.
