Mullard Magic: For All Your Vintage Valve and Radio Needs!
ML4 MARCONI OSRAM ST SHAPED TESTED
ML4, MARCONI OSRAM, AIR MINISTRY, 10E/17,
ML4, MARCONI OSRAM, ST SHAPED, TESTED
ML4, MARCONI, LARGE OVAL CARTOUCHE
ML4, MARCONI, MWT LOGO, BROWN BASE, MATCHED PAIR, 1961 MANUFACTURE