There are quality designators on at least some Russian tube types. the -E means extended service life. -B is the thing we really want to see as audiophools, as it means low noise. So -EB is usually the grail tube of a given kind, also -EV and -DR. Don't know if there are 6C45pi-EBs, etc. -EH is not the same designator AFAIK, pretty sure it simply indicates that Electro Harmonix is selling it.
Gold pins often just means that someone has a plating set, unless it is a tube that has some historical precedent like an Amperex gold pin 7308.
