Perry, have you thought about contacting Marsha!l Buck himself at CMA?
Although the models were built many years ago he might still have a few odds and ends tucked away that might just be some of the bits missing from your acquisition. For what you picked it up for must have been the bargain of a lifetime, so restored it will become a valuable asset to you.
It intrigues me why when one buys such an expensive model it is not mounted permanently in a display case to avoid damage.