system
Given the following post, respond as if you're commenting on Reddit:
human
[40K]Could the Eldar repair the golden throne?

They seem to be far more advanced technologically speaking, so it should be relatively easy right? Also, wouldn't they want to do it? Helping humanity can't be much worse that getting a new chaos god, considering what happened the last time.
gpt
Maybe?

Part of the problem is that it is the Emperor's technology, specifically designed by him and higher-ups in the Mechanicus. Yes, the Eldar are more technologically advanced, but they have to have an understanding of the actual tech before they could do anything resembling maintenance.

Just because "Bill" is a rocket scientist doesn't mean that he knows everything about all rockets. He may be able to look at most rockets and start to figure them out, but ultimately you wouldn't want that guy doing repairs on it because he didn't design or build it. 

So, the answer is a resounding "maybe". Assuming the Eldar felt so inclined to help us rebuild something that would undoubtedly make us unstoppable, and assuming that anyone, especially the Custodes, would allow filthy Xenos to touch the holiest of the Imperium's tech, then it is possible. But even then, they are going to have to try to figure out a piece of incredibly old and complex technology that literally nobody has any idea how to work.