This (violet bracket) is an aftermarket A/C adaptor.
The A/C pulley (now missing) was originally mounted on the end of the adaptor.
The adaptor is bolted (red arrows) to the original Factory fan belt pulley.
The original pulley-to-crankshaft bolt can be accessed in the middle of the adaptor (green arrow).
You may need to use a ‘deep’ 3/8” drive socket for this.
Install the socket on the bolt and then attach a long-handle ratchet wrench.
Sell the adaptor on Pelican.
Someone will find a use.
Best,
Grady