nice score! (let me know if you want to part with any of those). they are US Navy Amperex, made in Holland, 1965 most likely. VR5 is the code for 7308s. the delta signifies made in holland. White is the earlier ink that Amperex used (generally). Should do well in a phono pre. Those are a low-noise variety of 6922.
-Ed
-Ed