That's quite a find and the sentimental value alone would be enough for me to tackle restoring the #5 and #6. Agree with everyone who's commented on the #110 - not worth the effort if you're looking to make these into users.
Here's a great walk through guide to plane restoration with a ton of detailed photos. I'll be doing this with a #5 pretty soon that'll end up as a gift.
http://www.majorpanic.com/handplane_restor1.htm