Help identify old plug? Only marking: CANNON ELEC. DIV. CO. pins: 1 4 (distance pins 1-4 = 1/2") (vert distance between pin rows, 3/8") 2 3 (distance pins 2-3 = 3/8") pins are straight rod, not spring banana inner diameter of connector (bakelite or hardrubber part), 1" style is like old RU/ SCR-183 style, straight threaded exit part on rear. Tnx, Hue Miller