The A60/62 Stock is of course used by the Metropolitan Line and, as is now normal practice with what is now known as the Sub-Surface Lines, the numbers are intended to reflect the year of manufacture.
Although the full electrification of the Metropolitan Line had been planned prior to World War II, it was not until 1959 that the final phase was started.
The first batch of 31 new trains, built by Cravens Ltd, began entry into passenger service in mid 1961. A second batch of trains, the A62 Stock which were almost identical to the A60 was ordered and production of these proceeded without interruption from the original batch.
All the trains were in service by the end of 1963.
Full details of the stock can be found in Brian Hardy's excellent book 'London Underground Rolling Stock'.
The following photos give a good view around the cab of what is now the oldest stock still in service with London Underground.