The public version of the plugin doesn't support that complete (and please understand there's a reason for that).

This is what I can tell you...
1) Go back to the plugin page ( https://forums.alliedmods.net/showthread.php?t=285258 )
2) Look at the "EXAMPLE WEAPON CONFIG" tab
3) Only set the "viewmodel" (and not "worldmodel")
4) Lastly.... very Important!!!.... Make sure the base weapon is a stock weapon (as in, Scattergun, Pistol, and Bat)

This way you will see the custom model in your hands, but every else will see the stock weapon and will not be invisible.

Thanks Crafting, I'll try it out and see if it works!