I finished up these connecting tubes today. They came out very well. I even rounded the ends a little.

So, now I need to make some mounting brackets to affix these pins to the sub panel. I originally considered making these out of 1/16" thick aluminum angle, but that seems like overkill. These brackets will see very little force, so I decided to bend the brackets out of some thinner .032 sheet.

I was shooting for a bracket height of .854 and ended up with .857. Good enough!

Here are the brackets, nearly finished.