(Best Value) EL37 Mullard UK black plate used/good double getters 1956 hairline crack in glass (73ma)
(Best Value) EL37 Mullard UK NOS gray plate double "O" getters 1960's hairline crack in glass created by getter halo pressed against glass (78ma)
EL37 Mullard gray plate used/good double "O" getter halos 1962 (68ma)
