General Service Body.
In the example below, the male former is mounted on a block of pine to allow it to pass deeper into the female mould.
The female mould is cut from a piece of 3mm MDF plus the thickness of the plastic to be used. The plastic is then attached to the female mould with tape and heated gently over a gas ring. This takes a little practice to get the plastic at the right "floppiness". But once you get the hang of it, the method can be used for many different types of shape. The male is then passed through the female and voila'. The shape just needs trimming to final size using craft knife/files/sandpaper.