Very often, the logo or symbol is stamped in the recess beneath the balance wheel.
Here are some scans from the "Catalogue Officiel des Pieces de Rhabillage pour Montres Suisses" (the Officical Swiss Watch Spare Parts Catalogue) circa 1949 that might help you identify the make of movement in your vintage Swiss watch from the movement symbol.
Overall Condition: Steel case is in excellent condition with light, even wear from from age and use. Before the quartz era, Bulova had a reputation like no other.
The Bulova Accutron was the world's first electronic wristwatch movement, utilising the high frequency vibrations of a tiny "tuning fork" rather than the oscillations of a mechanical balance wheel to regulate timing.: Swiss made, 15 jewels, manual wind, circa 1940'/1950's.Accutrons were worn on several of the early NASA space missions and were used in some of the onboard timing mechanisms. The Astronaut was modelled by NASA Astronaut Scott Carpenter in Paris Match magazine and was featured in the film Seven Days in May worn by Kirk Douglas in the role of Colonel Martin "Jiggs" Casey.: A contemporary interpretation of the classic "Tank Louis Cartier", the designs for which were first visualised by Louis Cartier in 1917 in homage to the armoured fighting vehicles of the allied troops.This will give a good idea of the manufacture date.
Maker of luxury timepieces and desk clocks, with a history dating back to the late 19th century, their representative symbol being a pointed tuning fork (a throwback to their orignal watch designs which included miniature tuning forks to keep the time).Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co.