I also liked the stock brown speaker covers in my westy but had to have
upgraded speakers.  A cut off wheel on a dremel tool cut the face of the
speaker covers off and then I made sure that the faces would sit flush and
gooped them on (actually used the goop tm stuff).  That was more than a year
ago and lots of heat, cold and slammed doors later with no issues.

Jonathan Poole
'83 AC Westy