Why don't you use Rcs::Parser module? (or even Rcs one!)

use Rcs::Parser;
use strict;
my $rcs=new Rcs::Parser;
$rcs->load("filename,v");
print "Last: ".$rcs->version() ." ".$rcs->date()."\n";
print "First: 1.1 ".$rcs->date("1.1") ."\n";
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