A remix to have a square stamp base and handle. It is slightly more rectangle than square by a few micrometers or millimeters due to snapping in blender won't show distance from center, so very hard to be exactly say 50x50mm, but just set it to be 50x50mm for example in cura and you will barely see any difference.

If anyone has any tips on how to show distance from center to get it perfectly square, do leave a comment on a video or text on what tool that can show distance.
(measuring tool doesn't follow snap point nor show while adjusting, only while still and not moving it)

Creality

Ender 3

No

No

Used blender to adjust each end of the stamp to be a square, and added triangular shapes upwards on the handle for extra strength. and stamp handle smaller to not be oversized when adjusting it ti be bigger or smaller. It is slightly more rectangle than square by a few micrometers or millimeters due to snapping in blender won't show distance from center, but just set it to be 50x50mm for example and you will barely see any difference.