Spitfire bits??

I have been going through some old boxes and came across the following parts, they came with a load of other Spitfire bits, I wonder if anyone can id them for me.

Part one is a spring loaded component which has the all important “300” number stamped on the casting and also the bracket. These numbers are 30027 426 (bracket) & 30035 173 (casting) I have no idea what this was for or indeed where it was located in a Spit, can anyone help on this one?

Part two is to me a mystery object, looks to be some kind of pump with a plunger handle, no 300 numbers but has the following HA44 HA753 A105691 1 and A107657 1, could this be a Hawker item? again I have no idea what it was for.

Part 3 is a control pully, does anyone recoginise it as Spitfire?

Last part has the following numbers on it Type 5216 Serial ACC/VPA 14534, SP209B and is dated 1/40 or a persume it is a date anyway. Stainless steel “arm” has A97965.

You may also see that many of the items have a sticker with some kind of reference number on them although they do not tie with any of the stamped numbers.

Hopefully the pics will upload in the same order as above.