My demo wasn't supposed to be comprehensive, just a proof of concept to get you going. SOW2 is probably overkill for what you need but if you like using sledgehammers to crack walnuts then it will do the job.
To add support for launchers to it just add another set of database arrays e.g.
You only need a separate magazine database if you know your launcher uses a magazine classname that is different from the weapon classname. In the code example above its only needed to support the WW4 javelin launcher.
SecondaryWeaponDB = ["","LAWLauncher","RPGLauncher","CarlgustavLauncher","AT4Launcher","WW4_JavelinLauncher"]
SecondaryMagazineDB = ["","LAWLauncher","RPGLauncher","CarlgustavLauncher","AT4Launcher","WW4_JavelinLauncherMag"]
In your saving script to detect what launcher the player has use secondaryweapon. Then search the database in the same way as in my example of saving a primary weapon.
For pistols you add another database e.g.
Detecting what pistol the player has is slightly more difficult, you need to use weapons to get an array of all the player's weapons then remove the player's primaryweapon and secondaryweapon to leave you with just the pistol.
SidearmDB = ["Beretta","Tokarev","CZ75","Revolver","Ingram","Skorpion"]
SidearmMagazineDB = ["BerettaMag","TokarevMag","CZ75Mag","RevolverMag","IngramMag","SkorpionMag"]
Ancillary equipment like hand grenades are harder still. You could use a seperate variable to store the quantity of each piece of ancillary equipment the player could possibly have. E.g. PlayerHandGrenades, PlayerSmokeGrenades, PlayerFlares etc etc. But this is very wasteful, a more efficient way is to pack multiple values into a single SOW saved value then unpack them when you load. A single SOW1 entry can store an integer in the range 0 to 999998, or 19 bit words if you like thinking in binary (as I do). So you could store 19 bool values in a single variable or perhaps four numbers between 0 and 16. Hopefully you see where I'm going with this... MWC uses this principle to reduce the number of stored values from 652 to 74.