For context, the weapons I am talking about are the default half life 2 weapons in the CC editor. Those weapons still use their default damage values, so compared to the rest of the guns on the server they have painfully low damage. My suggestion is to simply increase the damage for these weapons so that they can better fit into the current combat system. The original HL2 weapons in my opinion are really cool and fun to use, and I believe a simple damage balance can put these weapons to good use. they are pretty fun to use, after all.
Now I am not super into PVP or know much about balancing, so this could completely depend on what balance needs to be done, so here is my suggestion for the new damage values.
Pistol: 30 damage per shot
AR2: 25 damage per shot
SMG: 20 damage per shot
Shotgun: 80 Per Shot (Pellet amount adjusted however needed)
357: 100 Damage per shot
This is all open to change but I really hope we can put more light into these guns cause personally, I think they are pretty cool.