(!!!!!) (BEST OVERALL PAIR) EL37 Mullard NOS black base and brown base gray plate same build NOS 1962-1966 (90.5ma and 91.5ma)
(!!!!) (Best Overall Single 1957) EL37 Mullard black plate NOS (2) upside-down cup-shape getter halos 1957 (74ma)
(!!) (Pre-1955) EL37 Mullard branded Philips Miniwatt gray plate like new, small rattle inside base, made before 1955 (81ma)
(!!) (Pre-1955) EL37 Mullard like new gray plate, 1 upside-down "cup shape" getter halo, made on or before 1955 (91ma)
EL37 Mullard black plate used 1957 (63ma)
EL37 Mullard gray plate NOS 1960's double "O" getter halos (59ma)
EL37 Mullard gray plate used/good double "O" getter halos 1960's (60ma)
EL37 Mullard used 1956 (53ma)
