It is designed to be tight and hold on to the button (since it is thicker than the leather body).

I printed it using Creatilty Translusent PETG filament using 0.12 layer with tree support and mouse ears brim type. Not very satisfied visually, but it fits and works well. Might worth to tune some parameters so it would appear more transparent and less shiny. Or printing it in matte black color. Share your makes in comments!