LOL, Flor.
Take some of your scraps, old and new, you'll have to brake the urethane off the old so it will soak stain. You need an underlaying base color on the new, this sometimes doesn't even get close to the finnish color. Then start experimenting.
After you think you have found your match, try it in macro scale next to existing, it will need fine tuneing.
I have had great success in this, but it's very time consuming. Good luck.:Thumbs:
Bob