I added some new cards to give the deck some support. Raptor's favourite cards like King Rex, Serpent Night Dragon are a must. I added almost every single monster he used, the exceptions are Sword Arm of Dragon (too weak), Tyrant Dragon and Kaitoptera (anime card). I tried my best to stick with the old school theme and Rex.
8 normal level 1-4 monsters + 8 effect level 1-4 monsters: Basic normal monsters Rex used against Joey, and some new cards. Aside Gilasarus, Black Tyranno and Giant Rex, Rex Raptor did not use a single effect dinosaur monster, so I added some new dinos to power up this deck.
3 normal level 5-12 monsters + 3 effect level 5-12 monsters: Megazowler or Sword Arm of Dragon? It's a coin toss between them, I did pick Megazowler because of it's ATK. Ancient Dinobeast and Sauropod Brachion are optional cards, you can use Ultimate Tyranno, Superconductor Tyranno or Dark Dryceratops if you want to. Frostosaurus is an old cards, but it's remains one of the best level 6 normal monster out there.