not2easy - 12:47 am on Jul 9, 2013 (gmt 0)
g1smd has the answer I would use. If you are already using php includes in your html pages you can just replace the entire contents of the page with a few lines like:
Header( "HTTP/1.1 410 Gone" );
and save the html page with the same name it has always had. Google calls it a 410 and it is still a html page.
If you are not using php in your html pages you may need to check with your host for their recommended method to enable php parsing on html pages. The line I add to my .htaccess file may not work for your situation, but your host should be able to help, it is a very common practice.