Mullard ecc82 12au7 code help

[tulmkr]

Hi folks, Im new to the forum, but not to tube equipment. I have come across a few Mullard ecc82 12au7 tubes that all have the same codes on them. I am guessing that they are a matched triplet. I have been trying to look up the date codes for them, and I have to say I dont really know what Im looking for. I never really paid attention to them before, but these are brand new, and matched. The codes on the tubes are as follows....k61 b7j. There are also numbers at the top in white...1.10.7.
If anyone has any info, or can steer me in the right direction Id sure appreciate it.

 

[Parafeed813]

k6 = ECC82, the '1' probably means 1st revision.
B7j = Blackburn factory, 19x7, october.
I don't know about white codes, but the 10 and 7 seem consistent with 'october' and a '7' year.

 

[DF96]

Same codes does not mean matched. It just means they were made in the same factory in the same week/month. Not even necessarily on the same production line.