I was working on a very similar design with a kumiko interface, and happened to see the model this is remixed from, so I decided to download and remix theirs instead of reinventing the wheel.

The most obvious difference is the panel interface is a kumiko pattern, but all of the differences are as follows:

• whole model resized to take up more space on the X1-Carbon
• connector pins added with tapered mid-point, in case you want a fully 3D printable solution
• beveled holes to match the connector pins on one side
• Insert/Interface panel redesigned to use kumiko pattern

For the connector pins, they're not a super tight fit when printed on the X1C, so I have the pins super-glued in both sides.

*Edit

I created a base for the moss pole with threaded stakes to hold your pole in place. There are two different sized stakes 5.5 inches and 9 inches. I would still recommend using super glue to hold the pole to the base - especially if you're putting more than 1 or 2 poles tall on top of it. You don't need to glue the stakes into the base. you can just screw them in.