Hi there, since the hard drive shows itself in Mac Finder, then it's possible to recover the old Photo Library on it via data recovery software.
You're recommended to use iBoysoft Data Recovery to complete the general file recovery, which is able to do disk scanning and data recovery fabulously with wonderful disk scanning techniques and data recovery algorithms.
Read to know how to recover the old Photo Library from the corrupted hard drive:
1. Click the Download button below and install it on your device.
2. Select the corrupted drive from the drive list and click Search for Lost Data to begin the disk scanning process.
3. When the scanning process ends, click Preview to check the recovery results.
4. Select the files you need and click the Recover button to restore the files on the corrupted drive.
Good luck~