Lancaster parts I.D. please..?

Hi Folks,

I was given some parts of a crashed lancaster by a French farmer earlier this year. The aircraft was shot down in 1944 in northern France. The large black casing has a large ‘S’ with the number 69 written across the ‘S’. What looks like a tyre valve is made of brass, is about 1/4 inch round and threaded on one end. The remaining piece looks like some kiind of spring.

Thank you in advance !