Agree with vinylvalet…i have heard the same from several sources as well. Tube sellers charge a premium for high test results that may or not be a true indication tube health or SQ and say different. Buying tubes new or old stock is always a risk but test results are helpful for minimizing that risk. I much prefer old stock preamp tubes for their SQ and durability.
Check out this link that explains more: https://geekmusician.com/do-preamp-tubes-need-to-be-matched/