The A500 floppy drive is (commonly) a Chinon FB-354, the same as in the A2000 and A3000, but it does not have a faceplate. It will also fit in the A4000 (replacing the FB-357A HD floppy drive, but obviuosly you will no longer have the possibility to read HD disks) If you are going to replace a faulty drive, you can simply move the faceplate (A2000/A4000) or the button (A3000) over to the 'naked' A500 drive.
So yes, it will work just fine, and even look nice.
-Paul