It is to be expected that 70 year older Oak would be darker and potentially have some different grain characteristics than newer wood. Are they using oil based poly? If so, my suggestion would be to have them add some stain to the next coat of poly. We've had success adding up to 8oz. of stain per gallon of poly. We use Duraseal stains and oil poly and have had no compatibility issues. Since they have a coat of poly on, they can do test colors on the floor and wipe them off as they try to pinpoint the right mix. It may require something other than Golden Brown to match the color, like Antique, Chestnut or something else. It's important to let the final sample dry because I've seen it get darker as it dries. 8oz. per gallon is the maximum we've used. They might not need to go that dark. It's better to go a little light than to end up going too dark.
They could have used different stains but that can be tricky. On Oak you have the lighter colored hard grain and the darker springwood. You might darken the lighter portion to match the older floor only to have the soft grain get too dark.
The stain mix causes the poly to dry shiny but the final clear coat will dry to the gloss level intended.