Hi Christine
I do not know when 007 was published, but I do have a bit of history on the dialing codes:
In 1960 the world was divided into "zones". North & Central America=zone 1, Europe+3&4, etc.
For some reason, the codes for the USSR were 68&69. These codes were used by operators. Over the years there have been many changes & the UUSR was given zone 7- the only country in this zone, in 1964. Whether one uses the 00 or not depends on where one is calling from. All this is regulated by the ITC [as CCITT] which is now part of the UN. The codes were worked out by AT&T [Bell Labs] and the other major telephone companies, most of which were nationalized. This was to get a uniform system of dialing working.
The system actually goes back to the 1840's with telegraph & 1920's with radio codes, but that is a different story.
There are still a lot of unassigned codes, but a new countries [namely former Sovet states] naturally want their own code, they may not conform to the original geographic zone system. That does not matter, though, as that was mainly just cosmetic id-ing, had nothing to do with the actual routing of the call.
Cheers,
Robert