I would adjust both shoes.
a brake gets grabby from contamination, whether it is bit of brake fluid seepage, water from condensation and the drums rusted, or something else. You might try moving it a it down the driveway or some other stretch of pavement with the brakes lightly applied. That may get them working ok so you can get to a place that is better suited for working on it. When my wife's 68 Mustang sits for a while (a month or up to 6) one of the front brakes is real grabby, once I drive it for 20 feet or so with the brakes applied a bit, it settles down and is ok again. My father in law had an International pickup that the rear brakes did the same thing. Every time they drove it, they had to drag the brakes slightly for the first 1/2 block or else the rears would lock up when they hit the brakes coming up to a stop sign!
