Help Identifying this vintage stopwatch please...Thank-you!

I am in desperate need of help Identifying the model of this vintage Heuer stopwatch. any help would be greatly app

The ref number should be heuer 540/22: 1/5th of a second, split action (rattrapante) function, produced in the 1970's. It was used for cars competitions, and it is definitely more rare than the usual 1/5th of a second stopwatches. Yours looks in very good conditions: would you tell us the story of your stopwatch?

Hi Albertoct--Thank-you for you most thoughtful and comprehensive information! I am deeply grateful. You are correct, the stopwatch is in near mint condition and appears to have been used very little. As for the background and story behind my stopwatch. Well, I wish it was a bit more glamorous but I shop estate sales in the metro Detroit area on a weekly basis. This particular piece was purchased on a whim at an estate sale in an area called Grosse Pointe, MI. This area tends to be one of the more affluent areas of Detroit and one where most of the old "industrial/automotive" family money remains. This sale was primarily a guys sale, ie. new old stock car emblems, car parts, tools...and I mostly shop for girlie things. I like anything that sparkles or makes a woman more beautiful. Lol Since there really wasn't much of that stuff here, I resorted to purchasing something I know a bit about which is watches. This was the only "watch" type item there and was priced what I considered fair. So, that is the story behind the stopwatch. Any idea on a value for this piece? Thank-you again for all of the information.

Considering the model and the conditions, IMO the value should be above 300 $.

I have a Heuer ref. 571in good condition,face is in very good condition,the back has some wear on the black surface. In 1972 I was at a vintage car race at Limerock park in Ct. I had a Porsche Carrera 906. A fellow racer came up to me and we started talking about our cars, he was driving a Birdcage Maserati. He asked if I would mind if he could drive the 906 and I said only if I can drive yours. [honestly] we drove both cars into the town, got some coffee and went back to the track. He gave me this watch as a thank you. Had a blast racing that afternoon. Can you tell me the years it was produced and a valuation.

By the way, that was 50 years ago, a much simpler time in our lives