I doubt that the two tubes are rebranded versions of each other, or of tubes from any other manufacturer, apart from the possibility that the Amperex may have been made by Philips, which acquired Amperex in the 1950's. RCA and the Amperex brand (both before and after its acquisition by Philips) were both tube oem's (original equipment manufacturers).
They both made quality tubes, as well. If the Amperex has a "bugle boy" logo on it, it is particularly well regarded (and valuable).
As the others have said, if the seller selected tubes that measure close to each other I wouldn't worry about it any further. And RCprince makes a good point too, that depending on the circuit design it's possible that there is no need for them to match, anyway.
Regards,
-- Al
They both made quality tubes, as well. If the Amperex has a "bugle boy" logo on it, it is particularly well regarded (and valuable).
As the others have said, if the seller selected tubes that measure close to each other I wouldn't worry about it any further. And RCprince makes a good point too, that depending on the circuit design it's possible that there is no need for them to match, anyway.
Regards,
-- Al