I read a lot and don't post much, but I've been around here for years. Anyway, the more I look at this watch the more I wonder what has been changed out over the years. Not having another close at hand to check against I have to ask those who've seen a few to let me know what's what with this. Disclosure, I have been contemplating letting this watch go. I've had it since the early 1990's, it was cleaned and adjusted in 2009 and I've worn it maybe 25 times in the last 10 years. I originally purchased it from a gentleman who was a vintage racer and claimed to have had it for over 20 years and wore it regularly.

Looking closely I believe the stop-watch second hand is replaced - just doesn't look right. I'm confused about if it should have the poly back with this dial and should the crown be signed, etc.

I've read too much and it has caused my head to spin.

Serial number is 568XX (on the below photo I smeared the last two digits, they are clear on the watch)
Model number - not stamped (possibly worn off, but S/N is clear)
Poly back
"Ed Heuer & Co. SA" on bridge
Heuer logo crown

Any thoughts you have are welcome. Thank you.