Uh-1B

I have been looking for a UH-1 for several years for experimental exhibition
as a war bird. I have found two of them with no paperwork no log books no
traceable bill of sale to the U.S. Government for the original sale or for
that matter to the last owner. I have been told this is not that unusual
that paperwork sometimes gets lost. My point is that since the paperwork is
non existent the value of the UH-1 is that on a museum piece and that of a
few other parts like the skids and some other parts that are not time life.
Just what kind of value is there in a complete but without paperwork UH-1B.
Seems like museum people offer large tax deduction value but little cash
somewhat inflating the true value of what they have. Can somebody offer some
kind of advice on the value issue and ownership?