Hi Duubz,
If you right-click on a folder in the content browser, there is a ‘fixup redirectors’ function. I’m doubtful this will help in your situation, but wanted to mention it.
If you select an asset in the level, you can press CTRL + C , and then paste (ctrl + v) that asset wherever. (Try selecting just 1 asset, and then copy/pasting into a text editor) You’ll see the file path that the object is using/expecting.
SO using this asset placement data, and maybe just pasting it into a new level or project that has the expected paths could be a win. (Or maybe manually editing the text with some sort of find + replace function then pasting)
With regards to the static meshes losing their material references. It might be best to re-add the content pack so all the references are re-linked. (And once you grok the file path thing, you might just be able to replace the already existing(but with broken refs) meshes with the new (fixed refs) ones)
Hope that helps!