6 black 1991 hunter original ceiling fans with a Rare matching serial number?

Took these six fans down today in 45 minutes, came out of former offices to a construction company. All six were oiled and taken care of as far as I can tell. When I was unloading them, I noticed 2 have matching serial numbers which I’ve never seen before.

[@CeilingfansViceCity1986]

I never seen this before on a original