That's a good question.

I can't think of anywhere off the top of my head that they might be archived, but it would be odd if they weren't somewhere. I'll have to investigate.

[edit]

Somebody made a list on the SSSSForum of the illustrations Minna posted in the author notes, aaaand you can find that here.

It doesn't look like there is any backup of SSSS vote bait, though. Only the aRTD stuff, which was posted on her blog here.