The foam filter has fallen apart so I'll need to get some from somewhere.The air cleaner foam may clean with your carb spray or even washing up liquid - so long as it doesn’t fall apart of course!
I don’t think those screws are the pacman type, rather round with a flat edge but give the tool you have a try.
WD40 won’t do any harm.
The carb looks like a Zama, look for a C1Q stamp and a three digit number somewhere.
John
The sheet of foam filter medium is fine for you, it can be cut to size or doubled up
That is for the air filter, the fuel filter is on the end of the tubing, inside the petrol tank.
You don’t need the air filter in order to start the machine.
John
Lets get this right.....a closed choke means the choke is on and the air passage into the carb is blocked - only used for starting.
One started the choke should be fully open.
If you have to 'juggle' the choke setting to keep the machine running, this indicates a carburettor fault or adjustment needed.
John