I made this in fusion so I could still have the runout sensor and run the filament from the side. I used M3 thread inserts for the filament runout and a small chunk of PTFE tube I had laying around with the connector for the routing of the filament. and I used some longer screws that fit the top reel mount holes but I think the ones that come with it will reach. 

I used PLA+ with 4 walls and 25% infill for strength but im sure you could use less.