Here's a model of a battery cover for Tonewood guitar amp. After mine was lost I 3d printed a new one and it did fit almost from the first try. Would recommend to be prapared to sand a bit as the designed part is a bit longer than supposed to be. However, it was not worth reprinting it so I left it as is on the image.
Have changed the + and - signs from outside to inside to print on the bigger surface. But would recommend printing it on the legs with supports instead for better outside quality.
Here are some of the settings I have used with my Ender 3v2: Temperatures - 210 nozzle, 65 bed Super quality (layer height - 0.12mm) Enable ironing on the highest layer only