Yay, thanks for this! This'll give me a reason to play Red again.
Have you added anything other than simply difficulty and availability of all the Pokémon? I know it makes it more of a personal hack rather than just a 151 hack, but it would make it more interesting, and attract others to the game. For example, adding a Pokémon event here or there, a new trainer(s), different sprites, maybe different hero/heroine characters, etc. Just a thought.