Unable to transfer Keychain data
I'm trying to copy keychain info from one Mac to another, from an old Mac Pro running El Cap, to a new Mac Pro running Sierra.
In the ~/Library/Keychains folder there is no Login.keychain, just three items: aspd.keychain, System.keychain and System.keychain-orig, but if I try to import any of these to Keychain Access on the new machine, they are all greyed out.
Exporting individual items from the old machine's Keychain Access doesn't seem to work either - I can select items, but the Export command is always greyed out - in both cases Keychain Access is unlocked.
Btw, I did import my user data using Migration Assistant, but none of the Keychain items appear to have been copied.
How can i transfer my Keychain data?