Gez wrote:What would be needed to write a tool doing that?
Can't speak for the floppy version, but for CDs you would first need to do raw CD IO in order to dump an image of the Mac file system. I don't suspect this would be too difficult to do. Next one would need to read enough HFS in order to find the relevant binary files and their data and resource forks (ECWolf technically only needs the latter). Once you find that, wrap the data into a macbinary container which you can find format details on a link in my Feb 2012 weblog entry.
The linked thread covers HFSExplorer which does the first and second part of that. The issue there is it dumps in AppleDouble format which isn't really suitable for ECWolf (there's nothing technically wrong with just renaming the resource fork file to something reasonable, but then it's no longer a valid AppleDouble which by definition has the resource fork as a hidden file named "._<filenamehere>"). So the simplest thing to do would be to either write a program which converts an AppleDouble to MacBinary or perhaps see if the maintainer of HFSExplorer would take a submission for an option to dump to MacBinary. (As stated in the other thread I would take a compromise on using AppleSingle if necessary, but I think it's more likely to find mods already in MacBinary format since it was more popular at the time.)