I believe my a/c clutch just died, am I correct about this or is there more than meets my untrained eye?

1990 Subaru Legacy
Anytime a/c was on there was a loud rattling noise, could also feel vibration through the gas pedal when depressed. A/C performance, however, was great--that is, minus the horrible noise and vibration the a/c worked as expected. Today, noise was exceptionally bad until heard loud snap and the air flow immediately stopped. I pulled over and looked under the hood to find that pieces on the front of the clutch were broken (some bend back toward pulley assembly and others bent outward) it seems that the front of the clutch was spinning in some anomalous fashion and these broken pieces actually began to cut into the adjacent bracket/brace attached to the compressor. Also, the entire front of the clutch seemed to be askew and no longer centered.

So I am assuming that the clutch broke and was the cause of the previous noise/vibration--is this correct, or could there be other problems with the compressor? If it is just the clutch, is it possible to only replace this part? I was looking online and only could find a compressor and clutch sold together and no individual clutches for sale. I hope this is not the case as having to buy the whole outfit is obviously much more expensive.

Please any comments or insight--I will be ever so appreciative.

Thanks,
Ryan