IMO, the only things worth looting in a Necropolis are the Beam Scatterer (lowers Laser range for higher damage) and the High Density Capacitor (consumes more energy for higher damage).
The rest?
Plasma Rifle: You’d never fire this. The ammo is one of the rarest spawns in the game, and this projectile causes a raging fire that destroys loot.
EMP Projector: Might be worth looting, but it’s likely you’ll never need this weapon. Plus, I found one on some dead scientists.
Leadworks Weapons: Honestly, does anyone even use these?
Rivtech Weapons: I got all mine in Labs, thank you very much.
Fusion Gun (I think it can be found here): Again, destroys loot. Causes a massive explosion making it useless at close range. Better off with a Fusion Blaster Rifle, or hell, even the Arm.
Electrolaser Conversion: Why the hell would you EVER use this? It makes Lasers less lethal and makes their ammo have the Beanbag Effect. Does that even effect the living dead? I’d much rather have an actual military grade Electrolaser, please.
Crap that can be easily found elsewhere: Curse you RNG!