Hey guys, sorry for no response, life got in the way and I abandoned the project on my end. I may look at picking it back up and improving on the design. The spacefox design looks like it may work more accurately, I hadn't come across that one!
Regarding buttons, I had started to try and figure out how to add buttons but I couldn't quite get my head around it at the time. I may revist it later this year. In terms of assembly instructions, search for "Space Mushroom" on instructables.
Thank you, I'm glad it has been somewhat useful!