Stupid question, what's the big deal with the Dart, and why does it need to expose the radar face?
you mean on the drawing or in reality?
reality
following this pdf :
http://www.otomelara.it/EN/Common/files ... TRALES.pdf
it is for taking out moving targets by steering the projectile in flight. this is done by an radio.... most likely this is the one which you called radar. why it has to be exposed? I have no idea, but it might be because the transmitter has to follow the projectile on it's flight, and this is easier without an cap over it. someone correct me if I'm wrong.
Parts systematization is a right thing to do for this site.
I noticed you're displaying the calibers now (except for Mk 75) which is good; and I actually think that some additional info never hurts. For example, the year when a gun became available, elevation, rate of fire and range would be very useful although it's just a little extra text.
I am not intentionally showing the caliber, but I am showing the names of the guns ( it should be clear that the mk75 is just an modified 76 compact). and for that other intel: maybe that will be done later on, but for now, just the use of good parts is more important then those things.