New 3DS XL Case - Ultra Clear Crystal Transparent Hard Shell Protective Case Cover Skin for New 2015 Nintendo 3DS XL LL - [New Modified Hinge-less Design]

A clear hard overshell might be a better option, and is probably cheaper than buying the filament and hardware listed on the maker page. (Assuming OP has a printer). The case you listed also doesn't address moisture and friction while playing. I've found good success with this case, just be careful clearing the tabs when installing. https://www.amazon.com/dp/B07VQ1ZHY1?ref_=ppx_hzod_image_mob_b_fed_asin_title_0_0