Shifter bushings made for the COBB short shifter 5-Speed. 
The tolerances on the outer ring might need to be a bit wider but that's something that tape can fix. As for the inner diameter, this was able to fit my application snugly. 
I recommend printing with PETG as PLA might warp due to temps inside the car during hotter seasons.

Inner diameter : 13.5mm
Outer diameter : 15.5mm