couple of questions if i may

on my own a4 i had a 2/4 seat so dont know what the std one looks like , i just dont think this one looks right , should it have a strap as well ?
i dont want to go mad with the changes and to be honest any will probably wait till winter so that i can use her in the meantime .
bearing in mind this is a relatively untouched bike but i would like to get it back to how it really should be !!
another pet hate of mine is Allen screws , of which there are a few

ie casings , chainguard any links or sources for cross heads and are they just bzp .
TIA