My comments about the valve and pieces of the cyilinder were quoted from a CNN video of a interview with the lead investigator. I can't find the video - but here is the story:
Valve in oxygen cylinder the culprit in 747 explosion - News - Travel
""We recovered a valve from an oxygen cylinder," Neville Blyth, a senior investigator with the Australian Transport and Safety Bureau, told a news conference yesterday. "It is likely that that valve is from the missing cylinder."
"The recovered valve is to be subjected to a forensic engineering examination at the ATSB's Canberra laboratory, where the cockpit voice recorder and flight data recorder are being downloaded. Maintenance records, including those for the oxygen supply system, are being scrutinised.
The valve had been found in the passenger cabin a couple of metres away from the bank of about six cylinders.
"The cabin floor of the aircraft has a hole approximately 20 centimetres in diameter above the location of the cylinders," Mr Blyth said. Asked if other 747s could have restrictions placed on them, Mr Blyth said a CASA representative was in Manila monitoring the investigation. This would allow for "any further safety action considered necessary", in addition to Qantas inspecting the oxygen systems on its 747 fleet, which is to happen by Friday."