I am trying to change a headlight. I can't can not

The headlight assembly (1993 Grand Caravan) is held in place with three plastic "wing nuts" that rotate on the ball-end (front end) of the adjusting screws. One "adjusting screw" (the one on the bottom, inboard side) is not for adjusting, just for mounting. The other two adjusting screws take a torx T15 in the front end of the screw.
Removing the headlight assembly is somewhat of a trick - it seems like it takes a special tool to reach the "wing nut" and turm it 1/4 turn (90 degrees) CLOCKWISE (so the "wings" are vertical). When all three of these mounting "wing nuts" have the wings vertical, the headlight assembly just pulls forward and off these mounting nuts. Place the new assembly back over the "nuts", turn the 3 "wing nuts" another quarter turn, and the new unit is mounted. Probably not even a need to re-adjust the headlights, but you should check.
The PROBLEM, is that it appears to take a special tool to reach and turn these wing nuts without breaking them (yes, the old ones get brittle). I tried a socket (did not work), and then long needle-nose pliers (broke one wing nut), then a 1/2" open-end wrench (which at least worked). However, pushing the new assembly back over the wing nuts, I broke another wing nut. So, I broke 2 of the 6, and one was broken when I started.
Now I need to find replacements for these "wing nuts" ... any ideas where to get them?
Of course I can use some washers, some nuts to fit the fine-threaded adjustment screw, and some sort of bushing (maybe cut a short piece of rubber tubing to fit over the adjustment screw). Place double nuts (second nut to lock the first in place) and a washer, then the bushing onto the adjusting screw, then the headlamp assembly onto the bushing, then add another washer, and two more nuts (not too tight) to lock it onto the adjusting screw (which must still be free to rotate). Repeat for each of the 6 mounting points. I have not tried this yet, but ... it should work.

Fabricate a tool to turn the "wing nuts" using a piece of 3/8 inch ID tubing which you file or cut 1/8 inch by 1/8 inch notches on each side of a diameter line.