One solution for making a power plug that I have never been
desperate enough to use (I have a cord with two insulated
alligator clips on the end for temporary --and very careful--
application) is to go to a model or large art store where
they sell very narrow metal tubes (2mm to 8mm+ OD).
Then:
force the tube over the prong.
cut to length
solder and shrink-wrap to power cord.
epoxy the pins to the right distance apart.
This I might test very carefully as well.
Not for construction by minors, etc.
John A.