The enclosure for the solar lamp is designed in Autodesk Fusion 360. I have designed many iterations to get this design. The enclosure has 5 parts:

1. Main Body

2. Top Cover

3. LED Holder

4. Diffuser

5. Button

The Main Body is basically designed to fit all the components including the battery. The top cover is to cover up the main body and mount the solar panel on it. The LED holder is used to hold the LED and the diffuser is used to diffuse the LED light in all directions. The button is used to operate the switch on the PCB from outside.

Download the .STL files from Thingiverse.