Advice on my GP Chronometer HF

Hello my fellow watch geeks,
Years ago I inherited this gorgeous GP Chronometer HF in 18K gold, hosting the 42.1 movement... Predecessor of the record breaker from the 60s and a ver serious hi beat movement. Ever since I git it I was scared to wear it, as I don't want to damage the delicate hi beat movement after decades of beeing in the safe. I would live to get more Infos from some real GP experts on this time piece. I'd love to know if the 18k bracelet is an original or an aftermarket band which simply got the GP logo. I'd also love an estimate of the current value of the watch as I am considering selling it in the future to buy a more durable every day wearer which will remind me of my beloved family members. I live in the West of Germany, if anyone knows a professional watch maker who is brave enough to take on that very special movement and do a service on it for a reasonable price, then I'd be more than happy about a suggestion (watch is running and holds time, yet u keep it i the hacking position, so that the mechanics don't get damaged without lubrication).
I'm looking forward to your expertise and I am more than happy to finally learn more about this very rare 18k gold beauty.

My advice, get it serviced and wear it.

I'd love to but yet I haven't found any watchmaker in my region who can service the watch... And do it for a reasonable price... I'd be incredibly happy about suggestions for watchmakers which have the skills to service this beauty.

Thanks a lot Tony, that is incredible, thank for the Infos for the watchmaker and this very quick response.

Could u let me know how much the service has cost you in the past for the 42.1, just out of curiosity to have an estimation.

Hm right, I haven't thought about that. One last question, if I may bother again. As you have earned multiple GPs in the past, can you tell if that bracelet is an original GP or an aftermarket bracelet... As they were quite common in the 70s as I read?
Cheers again and I really appreciate it

I can't help out in that regard, I live in Oklahoma.