Had it been me I would have painted the fairing two colours, with the windshield part black to represent glass/transparency and the rest whatever colour the bike is.
This does not help you as your bike is already black. Sorry.
However I am with the 'less is more' brigade, to the point where I would be hesitant to put any pin striping on at all. The fairing is too small and has too many angles for pin striping. So I would definately be very restrictive on how much I put on. It might make it too 'fussy'.
This is, of course my own personal oppinion and should be ignored at your own discretion.

You often see pinstipping on a bike on parts where there is a large amount of a single colour to break up an otherwise plain exteria. Tanks and fairings that are all rounded, etc, with few features to breakup the colour. This fairing is all angles and flat surfaces, and is a product of its time - the early 80's. The edges of the flat surfaces could be highlighted in a different way - i.e. with silver/gray detailing - but this is at odds with the style of the rest of your bike.
How about looking at the area that represents the wind shield and painting that instead with a colour that is different from the black but still represents the look of a darkened transparency? Or use a detailing line to delineate the top 'transpancy' section from the rest of the fairing and leave it at that?
You can see I am making this up as I go along.....
Cracking looking bike though.
Steve H