My L glass is weather sealed, but I've also shot in rain with the 6D and it's not come out the worse for wear (worst case, it shut down during one protest and then came right back after I let it dry in my vehicle).
That being said, one of the reasons I'm looking at higher end RF bodies is for the better weather sealing. I often shoot in New England or other places where the rain just won't cooperate with you.
Vuescan, but also I would take the time to listen to some Jason Scott podcasts - he's one of the digital archivers behind the Internet Archive (among many, many other talents) and has put in a lot of hours into troubleshooting scanning both documents and photos.