It's a 6 ribbed pulley for the "keyway" slot compressor for a Ford.
I have the Ford part numbers, but unfortunately, they are no longer valid
in the Ford parts system (determined this last year).
When I was boneyarding, there was a 85 Camry that had a ribbed belt.
Due to it's tight fit, I wasn't in the mood to pull it as an available option.
Currently, I'm considering a move to R134A, using a 93+ compressor.
It will require adapter fittings, but I can have these machined.