Buck moved from southern California to Idaho a little over two years ago. They cleaned house at that time. They have nothing left for the Buckmaster or the M9 bayonet. I know this for a fact because I had been in touch with Joe Houser at Buck at the time looking to purchace any parts that they had. They did run across some old M9 blades and assembled them with parts they had kicking around the shop. I wrote a brief article about these bayonets that you can view here:
http://www.usmilitaryknives.com/bill_porter_ii.htm