Circa 1968 Autavia 2446c GMT. The suffix 'c' is for compression type caseback.
Managed to source a box and correct bracelet but on me it looks and feels so much better on a NATO.
I did run into difficulties a few years back tracking down an hour wheel for the 24hr hand.
The V/J 72-4 is quite a rare find these days and I was on the verge of cannibalizing an old Enicar Jet-Graph for spares - fortunately one turned up just in time :-)
Also the same movement in a Zodiac and Breitling of the late 60's.
UPDATE: 23rd June 2010 - Back from service @ TAG with shiny new bezel http://24heuer.blogspot.com/2010/06/2446c-gmt-back-from-tag-heuer-mixed.html