Hi Robert
Sitting in a tin can, high above the world. One of my favourites. Nice touch that your line the second time says there is something that can be done. Plagarism? I prefer to think of it as 'the folk process.' If it's good enough for the likes of Bob Dylan, who has borrowed both lyrics and melodies throughout his career, I reckon it's good enough for you and me. Always enjoy your lyrics and singing and this is another fine piece of work.
Regards,
Leon