i know the feeling of the rubbish you find, i was amazed and at the same time pretty annoyed at the rubbish people have buried in the past.
i have just started digging over again after the first year of growing (mainly potatoes) and it is a lot easier with the roots and rubbish to dig up and clear. trying to do little and often as i felt like i almost broke my back earlier in the year.
keep up the good work.