The Kiss and Promentory (track 3 and 6 on cd soundtrack) are the pretty much the same song, they are bads on the song called "The Gael" by Dougie Maclean. I have been looking for the sheet music as well and I have found a site that has it: http://www.mohicanpress.com/mo11103.html it also tells you a little about it, and there is a mp3 that will play you the really song. If I find any more I will let you know.
I printed that sheet music from that web site and it did not sound right, so it may not be what you are looking for sorry. I do have to main theme part for the piano, and will be trying to do it by ear on the violin, if not that then my music teacher will help me get it for the violin. I will let know when I get some music.
You said you have piano music from The Last of the Mohicans. I am playing for a wedding on March 22nd and they want me to play 'The Kiss' from the soundtrack. If you could scan the piano music and send it to me, or tell me where you found it, that would be great!!