Apache Camper Sidewall Turn Button for 3D Printing

This is my take on the sidewall turn button to hold on the telescoping-arm covers on Apache Campers. I designed this with the goal of it being able to be easily printed in one piece with no support. Support can be used if your printer has trouble with bridging but shouldn't be needed otherwise.
I've got two versions: One with a threaded hole at the top and one without. I made the threaded version to perfectly fit a modern #8 sheet metal screw. I used a 1.25" sheet metal screw to reattach these to the sidewalls on my camper. With the threading already built into the part it reduces the chances of layer separation and cracking as the part is tightened down. If you still have the original sidewall screws, or want to use a different type, I've included an un-threaded version as well.

If the rubber O-Rings that go around the top are as crusty and dried as they were on my camper, they can easily be replaced with a #5 O-Ring from the plumbing department at most big-box hardware sto