ROTTEN COMPUTER ate my post while i was still typing.... ok starting over....I see that step #11 is to put the seat plate back, so that answers that question..
Fuse holder for hte lights is missing that little circle cover/plug that holds the fuse in. Is that going to be a dealer only-item or is there a better source for them?
The fuse holders are common parts, an auto store or electronics shop would have access to these, they may not be the same but if you get 2 to match you are set, just replace the entire holder not just the cap.
I don't remember a filter screen..... There should be a valve at the base of the fuel tank where the fuel lines run, turn it off and you won't loose too much fuel.
The only screw i remember on the Deutz engine for fuel was the bleed screw, open that up and pump the lift pump and you got a mess of fuel leaking all over the place, great to clean any oil but really smelly.
Hopefully that will give you a bit of help.