This sounds crazy but might actually make sense if you open your opinion for a second.What about nothing onscreen but the tickmarks and maybe the bearing overlay and having the monitors bezel act like the edges of viewport.Its not far from reality considering when you would look thru a scope you really dont see the lens piece your looking thru.You would see exactly what you see in this pic below.
IMAGE....
http://img4.imageshack.us/img4/7900/ss200scope2.jpg....
Watch this video of SH5 from 1:10 on.The player goes to the scope at 1:20 and then the scope is removed/the ship is magnified and.....you have to imagine scale marks and a bearing overlay and the staidmeter and RAOFB buttons onscreen also but you will get what I mean.