Due to a possible security breach, I recently had to wipe my Macbook and do a fresh 10.8.2 install without restoring from the possibly compromised backup. There's some information in my old system keychain that I wanted to bring over. I copied System.keychain into ~/tmp from the backup and added it using Keychain Access.
Now I have two system keychains, the old one and the new one. I can unlock the old system keychain with my current system password, but if I try to "show password" it wants "the keychain password". I've tried the current system password, the old system password, and every other password I could think of. Same problem if I try to move an entry from the old keychain to the new one.
I used the same technique for my login keychain and it worked using my old system password.
Is there any way to access the old system keychain? I still have the backups of the system it came from.