Hello, i have read your project description, i understand what you want, and i would like to offer you my services. I can create the 301 redirects for your 404 pages as requested, i will need the list of the 404 URLs to get this project done. I have done this many times, so i can finish this project quickly and to your full satisfaction. Feel free to contact me by private message to discuss the details. I'm looking forward to our cooperation.