Radio treated porcelains, clockwise starting from the far left OB 74, sort of an olive-brown RT

SOBT 81 (ST = silent type), rose coloured RT

NGK Japan 90, a dark burgundy RT

NGK Japan 85, a dark burgundy RT

(Triangle ) Japan (small brown)

PLH ANSI 55-2 Columbia 1997 249

Lorenzetti 1992 Brazil

W (in a circle)

OB

CP 84 ( in the centre of the group)