I'm afraid there's not!
On the Evo 3, the nuts just snug up against the Backing Strip, which rotates up and down with the pins (i.e. The Backing Strip remains parallel with the Axle Beam while rotating). I guess in this case the nut against the backing Plate acts as a "locknut".
However on the Evo 13-32 that I'm working on, there are just the washers (#10 in my original pic), which I presume go between the Axle Beam and the Backing Plate, as does washer #16 which is on the Pivot Bolt.
In replacing the nuts (which were already on the pins), I decided to add flat washers behind the Backing Plate, to perform the same sliding function as the Evo 3 Backing Strip. Partly I did this because the arced grooves in the Backing Strip have been worn out of shape (presumably due to movement in the pivot bolt and bush at some time) and I didn't want the nuts to jam in these grooves. This leaves no room for a locknut, or even a spring washer.
I will look at whether there is room to leave these (new) washers off, and instead use nuts and lock-nuts, as you advise.
Cheers
