I'm trying to identify an old heuer stopwatch that I've come across (see photos below). 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 (a "flyback"). The mechanism is intact and it seems to run well. I got it opened up by a jeweler and found the following info:

- Inside of casing has Serial No. 255022, and "Ed Heuer & Co SWISS" written inside
- Watch Movement has Serial No. 259323 and "Unadjusted Seven7Jewels" written on it

The watch has an inner and outer case. Inside the outer case the dates of service were scratched in by jewelers years ago. The earliest service date is 1949. I've attached some pictures below showing what I found. Can anyone help me identify the year/model of this stopwatch? Is it an uncommon style? I haven't been able to find any other examples of the same stopwatch online.