Took out gas valve on my MCX Virtus, 16 inch, was so dirty I could not turn it. After cleaning valve, piston, etc. put everything back together but the only way I could get the gas valve to seat and turn was with hole used for leverage to turn the valve on the bottom. On my Rattler, hole is on the top. I pressed the locking button and turned the valve until it went in and can move it plus side to minus, but valve is upside down compared to Rattler. Any help appreciated.