Rebuild Messages Database with Imported Transcripts?

Hi. I noticed that I had deleted a bunch of Messages, which were syncing to iCloud. I could not restore them from backup files. So I went to an older laptop and copied all the ichat transcript files and attachments to my new laptop, from ~Library/Containers/com.apple.iChat/Data/Library/Archive and from /Attachments. I used a file syncing utility ensuring not to overwrite any of the newer files that had been created since migrating from the old laptop. I was hoping to see the older chats upon restarting my machine but they are not appearing. I still see only the newer messages, post-delete. I then tried temporarily copying all six of the Message DB files from ~Library/Messages to a temporary folder, hoping that Messages would rebuild the DB files with the newly imported transcripts and attachments, but after a restart Messages came up blank, with no messages appearing. I restored the DB files since then, and am back to normal, but still do not see the imported transcript messages.

Does anyone know how I might force Messages to rebuild the database to include all the transcript messages that I migrated from my old machine?

Thanks!