Are they the same needles though as the regular Needle Master set? If they are, you could buy them at Hobby Lobby and I think AC Moore (I don't have either of these stores nearby but I think they sell "Boye KnitMates" as they are called when sold by the piece.) Also I have seen the knitmates on craftforless.com, I think.
Cool set & what a great find! I'm looking at vintage Needle Masters on ebay and they go for a LOT, even not complete.