All of this back and forth about whether or not the tubes without the Global branding are counterfeit or in some way inferior seems kind of nuts to me. The simplest and most likely explanation is that the tubes are in fact identical, exactly as they appear to be, and they are simply branded differently for different markets. The Global branding is a deliberate attempt to sow confusion in Western markets so that 1) distributors are willing to invest in distributing them and 2) they can sell at a higher price.
NOS tubes are exactly the same with many Sylvania and GE tubes etc. etc. selling under many brand names for exactly the same tube.
Perhaps Grant Fidelity adds a separate testing step but the idea that they are getting superior tubes seems ridiculous. If it helps you sleep at night and you are willing to pay more then buy from them. Or assume the risk of a more difficult return and buy from an eBay or Aliexpress seller. But the idea that tubes that are internally identical but have different lettering are functionally different seems ludicrous.