...can be tortured into passing both the invoking class and method arguments

No torturing required... just omit the arrow :)

#!/usr/bin/perl -wl
use strict;

package base;
  sub func {
    print q{in }, __PACKAGE__, qq{ via $_[0] got $_[1]};
    }

package derived;
  our @ISA = qw(base);

package main;
  my $pack = 'derived';
  my $foo = 'fu';
  $pack->${\qq{${foo}nc}}(42);

__END__
in base via derived got 42
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Update: When you write

  $pack->${\qq{${foo}nc}}->(42);
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you're trying to call a subroutine named like what's returned by func() (here 1, the return value of the print) ...

Anyhow, some related food for thought:

#!/usr/bin/perl
use strict;
use warnings;

*{main::1} = sub { print "1() called with args: @_\n" };

main::1(42);          # 1() called with args: 42
main::1->(42);        # 1() called with args: 42
1->(42);              # 1() called with args: 42

main->${\1}(42);      # 1() called with args: main 42

no strict 'refs';
main->${\1}->(42);    # 1() called with args: main
                      # 1() called with args: 42
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(I particularly like the 1->(42) :)