Sylvania 5751 BPTM

There are some Sylvania 5751 BPTM '50'S tubes for sale on EBay from a guy in Sweden. The code on the tubes read DH and RFE.

Anyone with insight to these codes. I am trying to figure out if these are the JAN OR WA tubes that are so rare.
Hi I found this thread by googling those date codes trying to ID some 5751... did you ever find out if these tubes are WA or JAN?