Dating Triplex Windows (not quite as it might sound)

Dating Triplex Windows (not quite as it might sound).

My 1955 Series II Van has side windows fitted however the history supplied, with the van, and the log book differ, regarding when these windows were fitted. The Log Book states “Van with Side Windows” in 1968, whilst the written history suggests 1962. So which might be correct?

One way of checking is by the age of the windows. Cars made from the 1950s to the late 1970s, with Triplex windows, can be dated by what is known as the TRIPLEX CODE which is etched into toughened and laminated glass. It is the glass that can be dated, not the car, but if the glass has not been changed the car cannot be older than the glass.

How does this code work?

The YEAR CODE is in the nine letters making up the word TOUGHENED (or, for later curved front windscreens, LAMINATED). Look closely and there will be a dot below one of the letters which will give the year of the decade.

T = 1

O = 2

U = 3

G = 4

H = 5

E = 6

N = 7

E = 8

D = 9

No dot, or possibly a dot under a space after the D, = 0

The code also works for curved windscreens replacing the word TOUGHENED with LAMINATED.

The quarter of the year that the glass was made can be found by looking at dots above the T, R, E or X, or at the side of the T or X, of the TRIPLEX logo.

T = January / February / March

R = April / May / June

E = July / August / September

X = October / November / December

Using my van windows as an example:

The first picture is from the passenger door window, which I believe to be original to my van. The dot above the E, of TRIPLEX, is July / August / September and the dot below the H, of TOUGHENED, is 1955. The van was first registered in September 1955, so this agrees.

The second picture is of one of the rear side windows, all four are the same. The dot, before the T of Triplex is January / February / March whilst the dot below the first E of TOUGHENED is, assuming it is from the 1960s, 1966.

The rear side widows cannot have been fitted in 1962, as the written history suggests. My assumption is that either the side windows were held in stock from 1966 and fitted in 1968 or, in my opinion more likely that, the rear side windows were fitted in 1966 but the log book not changed until 1968.

I wonder, how many Morris Minors still have all their original windows?