T+T is more than just the model style - its the screenshake, the bullet sizes, the bullet damage, the bullet trail, the way the shotguns don't just shoot a ton of bullets but actually have a slug projectile right when it fires.
Frog demonstrated you can make a pack that feels like T+T without being T+T - the guns worked differently and felt different, but not so much that it felt like it should have been a standalone pack with a standalone ammo system.
If you recode and reorganize T+T files, please release a version of it publicly so people can use it to develop more addon packs.