I was wondering how often you guys run into this. I did a job today that called for a patch over old floor furnace patched it in and sanded the floor everything went smooth. Then when it came to 80 yr old wood matching new stuff I had to mix stain 4 times to get it close is this something that gets better with experience or is it always a guessing game. I prefer to pull it out of a closet or somewhere else in the home less conspicuous but the home owner said no way.

Flooring from different sources will never look EXACTLY the same. Yes, pulling it from a closet would almost guarentee a match. I patch floors all the time. If it's a newer floor (laid within the last 40 yrs.), I can usually match it pretty good. But real old, old growth wood is nearly impossible to match. Grain and color are just different, as is the milling. Don't worry about it. Just cover your butt in your contracts.