launcher" in reference to the facility which produced it. All four remaining original China Lake Model grenade launchers are on display in museums. Serial number 4 is at the National Navy UDT-SEAL Museum in Fort Pierce, Florida while serial number 13 is on display in the War Remnants Museum in Ho Chi Minh City, Vietnam. Serial number 2 is stored at the Naval History and Heritage Command in Washington DC. One additional launcher is on limited display in a military restricted US Navy facility at NSWC Crane. Improvements and contracts An effort to produce an improved version of the weapon began in 1992 when Samuel "Dutch" Hillenburg, a firearms writer specializing in military weapons, teamed up with master machinist Brian Fauci. In 2003, they achieved a breakthrough and were able to convince fellow writer and firearms enthusiast Captain Monty Mendenhall to finance their research effort. By 2004, they had a functional prototype and had formed Trident Enterprises Ltd. to continue their work on the project under government patent. Brian Fauci sold his improved upon military demonstration CSG/Trident China Lake Grenade Launchers to private parties after the contract for a Marine Corps replacement Grenade Launcher was cancelled in October 2009 with the selection of the M32. By 2009 Trident created nine China Lake reproduction launcher receivers. These launchers were separate from the ten Trident launchers connected to the Airtronic deal. The CSG/Trident China Lake launchers have increased reliability and improved cycling of action compared to the original. CSG also replaced most flat headed screws with hex headed screws. The butt stock recoil pads are filled solid on the CSG launchers instead of ventilated for padding as on the original China Lake launchers. No sling studs or swivels were installed initially on the Trident launchers, although they have threading for the installation of sling swivels. Manufacturing metals were upgraded with improved hardness treatments and metallurgy since the original China Lake development with both the Airtronic/Trident and CSG/Trident launchers. There are a total of nine privately owned China Lake grenade launchers accounted for inside the United States, plus the four original China Lake grenade launchers from the NAWS, which remain in only museums. 2007-2009 U.S. Defense Contract In June 2007, China Lake launchers were in limited production by two different companies offering the reproduction launchers to the U.S. military by way of defense contracts. At that time, the U.S. Military was approached with