Pair of closely match of ECC82/12AU7s.
Matched Etched Date code are Gf1 /B3C1C4 and Gf1/B1I3 .
Tubes have different labeling but more important is that they are produced from the same factory with identical plate structures.
Tested on TV7U where minimum value is 56.
Tube 1: 101/94
Tube 2: 94/101