I'm trying to identify an old heuer stopwatch that I've come across. It's a decimal minute stopwatch (i.e. counts hundredths of minutes on the dial, with 1 full revolution being 1 minute) and the smaller inner dial counts up to 30 minutes. I have looked at all of the catalogs on OnTheDash.com and haven't found a match. The font on the dial is a sytlized Serif font (most of the Heuer watches have fonts that aren't as stylized).

The stopwatch is a single crown function with side-slide. Pressing on the crown returns to zero while continuing to run. The mechanism is intact and it seems to run well. Here is a photo:

Can anyone identify what year/model this stopwatch is? I haven't opened it yet becuase I didn't want to damage it (I know very little about watch mechanisms).

Cheers,