"Detroit Steel Wheel", (way cool custom steel wheels) Page six of catalog has the old baby-moon clips. Interesting catalog.
Not to confuse with
"Detroit Wheels" (they sell all the common "mag" look wheels)
Wheel sizing is much different now than it was "back in the day". Your Quest will be quite an interesting adventure. Keep posting your findings, the moons and wheel centers and clips and nubs are all over the place, size-wise.
Best of luck, and thanks for your dedicated restoration of your rare trailer.