The guys over at L4Dmods have started cracking on custom Melee weapons, which the game supports surprisingly well. This only works with Melee weapons.
Very simple and temporary tutorial.
Riot Shield Mod, using scrapped melee weapon models, when Locally Hosting or Playing as Singelplayer, it has a chance to show up in all games.
Note: While looking through the models myself I found an unused w_didgeridoo.mdl, currently working on a weapon mod to see what that is.
