Hi.

Heuer made a number of watches in this style in the 1950s: http://www.calibre11.com/history-of-tag-heuer-1950s/

However, so did a number of other manufacturers and that makes the redone Heuer shield on your watch something of a concern. Some of the other details, like markers, aren't a match for known Heuers either, although it is certainly far from the best documented decade in Heuer's history.

Do you have any photos of the caseback and, even better, the movement? Those would help us to help you a bit better.

Mark