Plug threaded - OpenScad

On board a ship we have many plugs - for ballast, bilge, temperature sounding pipes, overflow boxes, masthouses etc. different size and shape.
Some of them are made from brass and happens that they disappear in the port.
So, I tried to find a remedy.

libraries used: threadlib.scad by Adrian Schlatter
regular shapes.scad by Giles Bathgate, Elmo Mäntynen