I'll lead this off by noting that this is a blatant attempt to see if someone else has done the work so I don't have to.
One of the things I noted recently going back through the core rules is that we have melee weapons and we have primitive armor, but there aren't any physical shields. The only active defense is blocking with a weapon at Formidable: Armed Martial Arts. Has anyone put together rules for shields, whether for TL1 neo-barbs or for TL7 police/gendarmerie with riot shields?