It's still difficult to identify those parts from the resolution but a couple of them make me think of short camloc fastener constituents.
Whatever they are, they had no right being in your tyre (or even on the workbench).

http://catalog.arconicfastenersandri...stud_small.jpg

100% not camloc parts - they are just too small - one is a small 'tube' maybe 1 -1.5mm diameter and 2mm long the others are similar but either solid or blocked maybe a little longer.

The FAA apparently are not interested in such things - I tried to get in touch with them, they will apparently meet with me personally - if I can get an appointment confirmed and would like to spend $3,000+ on the trip.

On the other hand if I do something wrong they will be very happy to meet with me as they can recover their costs.

I have a 1976 PA28 that went to the US three years ago tatty looking as heck but mechanically perfect - it has been in to separate shops, came back looking good but I have frightened when I fly it.

Yesterday I flew and found that the new flap link on the right side is not free moving like the other old flap connector and those on the ailerons - such that when the flap lever it lowered (to raise the flaps) it sticks - the damned thing is new I paid a week's income to have to fitted and find it to be rubbish - so another hulking bill beckons - there really are some scum in this world.

By the way on the 1976 PA 28 - costs over the past three years US$150,000+ and counting - hours flown 22!

In the two years prior to it going to the US - hours flown 400, total maintenance including annuals and 100 checks US$9,873!

The damned man hasn't even replied to my emails.