Congratulations on your purchases. Many people were wondering who the bidder was on the Forbidden Planet, especially since a couple of them sold recently at Heritage for less.
As long as you are happy with the purchases though, that is all that matters. They will certainly look great framed up and I hope you enjoy them.
Forbidden Planet and Cool Hand Luke appear at auction often enough that you should be able to get a good idea of their value.
The Disraeli of course is much rarer than the other two pieces and was part of a small find a few years back. The other copy of it (lesser condition) sold in an Emovieposter auction around that time (
http://www.emovieposter.com/agallery/archiveitem/14442241.html). I haven't heard of any other copies known than these two.