Hmmmm. I get a "404" at both URL's.

In 22 years of this hobby, RF and audio, I have used every material you
can shake a stick at, even gold.

Plastic, IMO, is for Saran wrap and should stay there ;-)

Wood, tin, copper, brass, aluminum and steel, in that order, are my
personal preferences.

For HF circuits, tin is a superb shield, soft enough to cut with scissors
and easily solderable. As long as your HF circuits are well shielded, the
outer cabinet is restricted only to the materials that will be needed to
withstand the abuse you want to put it through.

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca