If you could find out who is in possesion of the papers then you could ask them to transfer them to you. The papers belong to the registered owner not to the horse. Some people retain the papers because they don't want a horse to have registered off-spring or they don't want to be tied to the horse in any way but most often the transfer is just not done or the papers get lost. I don't know if AQHA will give you contact info for the previous owners but they may be able to contact them on your behalf to get the transfer.
There's nothing like the Rockies in the springtime... Nothing like the freedom in the air... And there ain't nothing better than draggin calves to the fire and there's nothing like the smell of burning hair. -Brenn Hill