Heuer Professional, Year and Dial

Hi,
I own this Heuer Professional since nearly 20 years. I have several vintage Heuers like Carreras… What I don‘t understand about this what is:
1. It is a 884-1 and when you look at the serial number, it seems to be a very early example.
2. So, why isn‘t it a Monnin? („Red letters“ and „Made in France“ on the dial)
3. Is there a 884-1 with this dial or did someone change the dial maybe?)
PS: Love the watch and hope someone can help?
Thank you!