Hmm...well Vlad's response should work. If you snap all the points back to one planar position then they will lie in a plane, which is what you want...
If you dont like that idea, you could possibly average the vertices, but this will never truely put them all on the same plane, but yet after a few they should be relatively close (hence 1/2 of a 1/2 of a 1/2, goes to 0, but never gets to 0).
The only other option is to just simply take your time and line up all the points by hand in all the different views. This will take forever, but at least you will be sure they line up.