Jack,
I don't think the squared or rounded notches make a difference in the mask (that is what Moss is calling part 15, adjuster and mask). The notched cam of the adjuster rests on the shoe and the stamped ridge of the mask. The front wheel cylinders have two guides to keep the mask located on the cylinder, the non-slotted shaft on the front adjuster is about 3/8" long. The rear wheel cylinder only has an outward locating ridge and the non-slotted shaft is a little over ½” long, and it rides against the back plate. If a front adjuster is used on the rear the shoe can walk inwards. I assume you are getting new springs and shoes, but for informational purposes the upper spring in your picture is one of two identical springs for each side of the front, the two lower springs are for the rear, one for each side on the wheel cylinder side of the axle. There is also a shorter heavier spring that goes on the other side of the axle that you don’t have pictured. So measure what the shaft length on those adjusters are and we’ll go from there. Have fun on your trip, we’re heading over in August.