Thank you for the speedy reply… I should have mentioned that I also copied the .ssh directory over (in order to log into all remote machines), which seemingly does not matter for this case.
Thank you for the links, I read theses… and took inspiration from this post: Keyrings problem - #9 by uHuH BUT, instead of deleting these, I renamed the existing directory and copied the keyrings from the backup; opened brave and viola, the passwords are back.