I’m very late on this, but the old Paul Revere buses on the 712/713 have been replaced by brand-new T buses, with announcements and all! They still use the awful Paul Revere fareboxes, so you still can’t use CharlieCards on the route, but it’s still a huge improvement. Here are some pictures!

The bus at Orient Heights.
The inside.

The bus leaving the Winthrop Ferry Terminal.
Coming…
Coming…

Coming…
There it is!