I adapted https://www.thingiverse.com/thing:1110599 to resize it to the proper width and thread pitch and change "43" on the back to "42".

It fits perfectly, but I've also since found another M42 bodycap on thingiverse, so take a look and pick whichever you prefer: https://www.thingiverse.com/thing:2864923

Creality

Ender 3

No

No

0.2

20%