Github is already enough. The code was available and you can even recycle the dead project by yourself. So why do wee need a digital crypto museum for this? There are also plenties of sites have been storing explanations and implications related to those dead coins with the unique utilities.
However, i know there is a place that already stored thousands of crypto repositories(an aggregate repositories) called
https://www.awesomecrypto.xyz/. So i think no need to create another one for that. Just make it as simple as possible.
Github is centralized. It can easily disappear, putting all of developers' hard work and effort at risk. That's why we need a decentralized solution that would help preserve data forever. Only important data, not all of it. Because if we were to store every single content from every single crypto, it would take up a lot of space which will result in time and resources wasted. I'd only choose old crypto projects with unique features not found anywhere else. Projects that are straight up clones from others would be discarded. Same goes for projects with minimal tweaks.
Like I've said, there would be a website that would serve as the front-end interface to access content hosted on a decentralized CDN. The one you've provided is nice, but certainly not enough. For what I know, content is hosted on a centralized server. If there's interest from the community to make a digital crypto museum, it will become a reality. Otherwise, not. Perhaps, it's best to download and preserve crypto repositories ourselves? I have many binaries and repositories stored on a HDD for future reference. If you're a true crypto enthusiast/lover, I'd suggest you do the same.