It's really a catch 22 situation. On one hand, your at the tail end of a flow and many times as the days shorten and the nights get cooler, the bees will backfill the brood chamber, causing some patterns to be questionable as she competes for space.
On the other hand, you mention that the hive numbers have dropped. And even though no two hives will ever be the same, you do have the knowledge of comparision, which makes this hive not up to par.
1) Many wait till its too late. For the cost of a new queen, it's a far better option than a dead hive later.
2) You have just experienced the power of summer splits, new queens, and the many benefits that go along with them, including reactivated brood production and diminished mite pressures. A couple months ago in Bee culture there was an article "Outbreeding Mites". And although I do not agree with everything the writer says, he does hit the nail on the head about mite control and a far superior fall brood period and associated winter preparation of the bees with newly installed summer queens.
If you can find a queen, requeening would not hurt.