Can you explain this a bit more? I don't understand what's the problem. I'm confused with "valid, paste". There's nothing to validate or paste. When you find cover online you have option to save it and also to embed it to file itself. From what I understand, guayadeqe shows covers from folder where the song is, so even if you have embedded cover it will be extracted and saved as cover.jpg in the folder where the song is.
In reality that didn't quite worked for me. Not all covers that were extracted was shown. So I had to rescan a library a few times and still some of them were missing so I had to point to them manually. But the good thing is that I had to do that only once. On each next full rescan they were there.

Like I said, for some albums covers are not detected even if they exists in folder. But after pointing to them with "Select Cover" option they appear. Don't know why. And also, even if you don't see cover in album browser you can see it when playing a song from that album.
If you don't have many albums maybe the best solution would be to edit them with easytag or some other tag editor or manually search for covers and saving them in the right folder with "cover.jpeg" name and then point to them manually if they don't appear after rescan. I have some 7000 albums and some 500 covers were missing so it took me a while to fix them but now it's OK. Even after installing new system and switching to svn guayadeque and couple of rescanning, even after deleting the database and rescanning everything is fine.

when you click "save cover" do you see them in the album folder? That should work as expected. At least I didn't have any issues with that. And one other thing, guayadeque doesn't show covers embedded into tracks if I'm right. Instead it extracts them from tracks automatically and save them as "cover.jpg". So if you have a folder with 50 songs from the 80's and they are all from a different albums and all are tagged correctly with the right cover embedded you will still end up with only one cover in album view. And if you try to save another one it will rewrite the old one.
I'm writing this just to clarify things, maybe it has nothing to do with your issues but just so that you understand how things actually works in guayadeque. If you have embedded cover in tracks but not one in folder guayadeque will extract it an save as "cover.jpg". If you do have a cover named 123.jpg guayadeque will pick it up during scanning but it will make a copy called "cover.jpg". In the end all the covers should be naed "covers.jpg" and then you shouldn't have any problems.

As far as I can tell it might be the files from different albums all in one directory and throwing the program off like mentioned above. It's possible Calypso is downloading them properly but the Album Browser view isn't showing them. I have this problem with some of mine as well. I found that you can easily see what albums have no cover art shown, you right click on it to download the cover art and it doesn't immediately refresh it onto the Album Browser view. After doing a collection update or rescan it shows it properly. If you already downloaded the cover and it's in the right directory but doesn't show in Album Browser view you can right click on it and click Select Cover and open the cover art file and it'll refresh on the Album Browser view screen immediately. Kind of weird, not sure what causes it.