In the meanwhile I joined forces with ryg who hosts https://rmarchiv.tk. The goal of the website is to preserve (German) RPG Maker games. In the meanwhile the site is also available in English and many non-German games were already added. Feel free to contribute if you want.
The focus should be on games that aren’t available on common websites (like rpgmaker net) anymore, just rehosting RMN games makes no sense ^^.
Here are multiple threads which list lost games, maybe you have one of them?
https://rmarchiv.tk/board/thread/8?page=1
https://rmarchiv.tk/board/thread/60?page=1
All game files are automatically backed up every night on multiple servers, when the site ever goes down we will still have all games.
Bonus: When you create an account you can play any RPG Maker 2000/2003 game in the EasyRPG Web Player and the savegames are stored in the cloud.