Glass id. According to John Tipler "Mini Cooper - the real
thing" (Courtesy of the Mini Cooper register).
!!!!!! pre 72  Mini's and Coopers !!!!!
 
Indestructo
This manufacturer was taken over by Triplex in 1968 and closed
down. The name is usually etched in an arch shape with two
letters under the bottom of each leg. The letters of interest
are the two underneath the letter 'I' of the company's name.
The letters below the 'O' should be ignored for dating purpo-
ses.
 
Of the two letters marked beneath the 'I', the one on the
extreme left is used to indicate the quarter of the year of
manufacture using the code word BRIT. B=1st, R=2nd, I=3rd and
T=4th quarter.
The year is indicated by the second letter below the 'I',
using the code word INDESTRUCTO. I=7 N=8 D=9 E=0 S=1 T=2 R=3
U=4 C=5 O=6
(The second 'T' was ignored, except for the first six months
of 1966 when T=6 and O was ignored).
This amounts to:
       Q1   Q2   Q3   Q4
1959 =           ID , TD
1960 = BE , RE , IE , TE
1961 = BS , RS , IS , TS
1962 = BT , RT , IT , TT
1963 = BR , RR , IR , TR
1964 = BU , RU , IU , TU
1965 = BC , RC , IC , TC
1966 = BT , RT , IO , TO
1967 = BI , RI , II , TI
1968?= BN , RN , IN , TN
 
Triplex.
 
The date code of this company is shown in dots above or below
words in the company motif.
The year is shown by a dot under one of the letters of the
word 'laminated' (where this applies to a windscreen) or
'toughened' (this being the most common). A dot under the
first letter of either  word represents a year ending in a
'1': e.g. 1961/1971. A dot under the second letter would
represent 1962/1972, and so on.
Although only a single dot is used the format showing which
letter represents each year is as follows -
LAMINATED   TOUGHENED
1234567890  1234567890
Prior to january 1969, only the quarter was shown using a dot
above the letters 'T', 'R', 'E' and 'X' of the word Triplex:
T-1st, R-2nd, E-3rd and X-4th.
     .
TRIPLEX
TOUGHENED = 3rd quarter 1964
   .
After january 1969 the month is shown by one, two, or three
dots above the letters 'T', 'R', 'E' and 'X' of the word
Triplex, as follows:
 
         .
January  Triplex
          .
february Triplex
              .
march    Triplex
               .
april    Triplex
         .
         .
may      Triplex
         .
         ..
june     Triplex
         .
         .    .
july     Triplex
         .
         .     .
august   Triplex
                .
          .     .
september Triplex
               .
         .     .
october  Triplex
               .
              ..
november Triplex
               .
               .
December Triplex
 
Example: may 1970 =
   .
   .
   Triplex toughened
                    .