How does one import .abcdp files into contacts?

GregRaven wrote:

After I upgraded computers, I noticed that I seemed to have thousands of contacts duplicated between iCloud and "On My Mac." So I deleted the ones under the On My Mac heading, and On My Mac disappeared, along with 90 percent of my contacts. I found the metadata for them in a backup file, and can preview each of them in the Finder, but Contacts app refuses to import them or recognize them when I manually add them to the Metadata folder in ~/Library/.../AddressBook. How in the world do I re-add these thousands of contacts back into my Contacts app?

see if there is anything here

how to import .abcdp files to contacts (m… - Apple Community

The metadata is no longer importable. Oddly, Apple still suggests making a Contacts Archive which merely copies the AddressBook folder. It used to work when the backing store files were vCards. However, they are now XML and those can’t be imported.

I’ve reported it several times but haven’t heard a peep from Apple

You might search for a utility that can convert the XML to a vCard.