Thanks for the recommendations everyone! I really wanted to use the factory original clip, but wasn't willing to tear the entire car apart to find the one that I lost. It fell down into the abyss (right side of the car, gas tank side).

A tip for anyone disassembling theirs - cover up the crevices or pack them with something to prevent small parts from falling down into those areas.

Anyway, I ended up buying a pair of 5/16" E-Clips (two in a pack) from the large Orange Box store, 60 cents for the pair. They worked fine. I'll save the factory original as a spare.

Oddly enough, the cable for the flaps on the hardshell tonneau cover uses e-clips. Mix and match?

And it's funny that one post mentioned asking Klaus at Top Hydraulics - his shop did the rebuild on the cylinders for me. I did have a leak after putting everything back together, I had spoiled one of the o-rings for the hydraulic hoses when reinstalling the cylinders. Good thing Top Hydraulics sends spares. Replaced and repaired without completely removing the cylinder again.

Everything back to normal. Thank you all for the advice. It wasn't the path I wanted to go, but it works fine. (Probably could have special ordered something from a dealer, but 60 cents plus tax is hard to argue with.)

--Joe