They arent tractor parts for sure. I think, they could well be aircraft parts. Im interested in this as Ive found a site in a field just down the road from me which was the site of a crash.
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A colleague Nobby Munday and myself cycled down to the meadow after school. We were both very interested in tanks and guns and to see so many aircraft in the skies everyday - these were very exciting times for young lads like us. A Warrant Officer stopped us going into the field. Well we were persistant little so and so's and eventually he let us in. The tail-plane, fuselage and wings had already been taken away, as well as the three bodies.
We searched the field and by jove they had made a very good job of clearing the wreckage. During the search I found a little brown satchel about 7 or 8 inches square and inside were the names of 3 airmen, all from Coventry and we handed this to the Warrent Officer. Also while searching the field I saw an object and dived on it immediately more to lay claim to having found it than anything else - and this turned out to be somebody's lung or other internal organ. I dropped it like a hot cake and didn't tell the Warrant Officer for obvious reasons.
The two engines were well embedded in the field, possibly 7 or 8 feet in the ground and we could see the metalwork of the engines around the two big holes in the ground and the stench of aviation fuel was very strong. After this we came away as we had seen as much as we could see. I'm not sure if they just filled in the holes and the engines or parts of them are still left in the ground."
Source
http://www.mkheritage.co.uk/hav/docs/war/war.html