That sounds like some of the stuff I see, @Seaitoverthere, only they're not buried but placed around the garden. Sometimes I get told why they're there, such as the hideous plastic gnome in one garden that turned out to have great sentimental value.
Marbles turn up fairly regularly and I now have a collection of all I've found. Some are quite old and are handmade.
I love that, bit by bit, gardens will start to give you the stories of who lived there before and hints of what might have gone on in the past.