I can absolutely attempt to fix it. It will cost you more (like 50k maybe) pus parts I might have to buy and shipping.

The NES is a stupid simple console. Just take it apart and clean with a brush and rubbing alcohol. If that doesn't work, just buy another one. They're pretty cheap. I don't know anything about modding either but I can't imagine there is much to do with the NES. I was always an Xbox primary guy so I can mod OG Xboxes and I know how to do various things for the 360 depending on the model.