Seeing this issue and having a CD copy of Blood in my possession, I would like to make a custom rip of the CD audio soundtrack with the track problem fixed for you guys. Would it be okay to upload the soundtrack fix here on GOG's Blood forum or not?
I don't think you'll be able to fit the files on the forum due to size restriction of attachments. You could always contact GOG and offer them correctly ripped CD audio files which they may then be able to put into their installer.
Another option would be to link to a file hosting site where you have uploaded the files but I don't know the legalities of this, and it is most likely illegal as the content is still copyrighted material.
I'd advise you to contact GOG first to see if you can sort something out with them. In any case, keep us informed of what happens as I'm sure we'd all like to get correct music for this game. :)