Thanks every one! I am happy to report I have found a perfect duplicate, like 99.9 % perfect. It's MAC's Fresh Brew. I'm going to try to post a picture.
What I had to do was, I followed all of your advice and found a full sized new, un-opened tube of my YSL 24 on Ebay, with the intention of sending a swatch to Three Custom Colors. But I had to travel to Chicago Monday so I took it to the MAC Counter at
Nordstrom and the Pro there took a lot of time to find a match for it. She was very sharp, and very determined! We were both amazed at the near perfection of the match.
You are all so helpful,
I am really grateful. And I'm going to try Three Custom Colors and see how close they get in case this ever happens again. I mean I've lost beloved shades before, but losing 24 after all this time was quite a blow. Anyway with all your help I'm out of mourning! I had no idea there were those great sites like TCC and Temptalia.