Thank you MrMacFixIt, your instructions worked perfectly. Virtually all of our 11,200 photos were restored from the backup on Time Machine with no duplication and with both thumbnails and full photo images. Final question re that procedure: can the IPhoto Library icon that I previously moved to the desktop now be trashed?
This problem -both the crash and backup- raises questions about a more reliable way to backup a large photo library such as ours which undoubtedly will continue to grow. Any suggestions? More immediately we seem to be having a problem with TimeMachine which is balking at doing any backups, claiming a need for 75 GB and having only 9 GB available (it's a 150 GB model). I think this problem was exacerbated by the inflation of our IPhoto Library from 38 to over 60 GB when the local tech did the restoration. Is there a way to start TimeMachine fresh again?