Ah... But, reading a little further down in the documentation for open...

    If you specify '<&=N', where N is a number, then Perl will do an
    equivalent of C's fdopen() of that file descriptor; this is more
    parsimonious of file descriptors.  For example:
 
       open(FILEHANDLE, "<&=$fd")
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So, using fileno() on your globs, you can dup your filehandles like in the open example, except with the numbers instead of the names! An updated snippet from your code:

# restore STDOUT
my $fd = fileno($this->{'_stdout'});
open(STDOUT, ">&=$fd");
print STDOUT "STDOUT restored\n";
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