I HAVE A OLD PALOMAR TUBE LINEAR, LOOKS LIKE 310 MODEL WITHOUT TOGGEL SWITCHES ON FRONT, OLDER MODEL, JUST PLATE AND LOAD, AND METER. I DONT KNOW THE MODEL NUMBER OR THE 2 TUBES INSIDE MODEL NUMBERS ARE, WOULD LIKE TO BUY NEW TUBES BUT RUBBED OFF OLD TUBES INSIDE. I CAN EMAIL PIC'S OF LINEAR FRONT AND BACK AND INSIDE. NO MARKINGS ON LINEAR FOR MODEL NUMBER AT ALL, PLZ HELP.