You need to make SURE these people know just what a valuable item this is. I've told people before about high value items, only to have them sell for a fraction of the true value.
A smart move would be to get an official appraisal, fully documented, and have this baby insured.
I saw one case of a man dying, and his son knowing nothing about guns, letting some slick antique dealer give him essentially nothing for them.
This one really should be in a museum so everyone can see what the West was won with.