OK been snowed in here the last few days and had some time to think some options out However they are based upon some lacking info I don't expect you to provide due to the secret nature of your endeavor
1 - You need to get to some of the Lincoln threads on this board and others . L C BAKER and KGC have done a lot of research maybe they can give you some info
2 - I feel your being honest , But how did this get to OHIO as you said , Booth crossed the river in Virginia ? Was it transported to the new location?
3 - I dig a lot in my quests , A lot of stuff was buried down here during the WAR , I have yet to have to did deeper than say 3 feet, A fellow member found a steel vault box in LA and it was only at 2 feet SIX feet is along way to dig , It is apparent there had to be some assistance , If so there has to be another map or person who is aware of the story besides you
4 - The best approach with the owners would at this point be honesty --- You don't have to mention what you feel the missing pages contain regarding the act, just offer them to them , at that point if there was any activity with the Holy Sea , you put the decision to release it with them , If they read it and discover the information, they can simply burn the pages and its lost forever , I would not let them know what you THINK the pages contain
5 - There is very strong opinions that Booth was part of the KGC and was not killed at the farm - There is a link to the Brooklyn NY newspaper the " Brooklyn Eagle " that indicates he still was alive for many years. That being said I don't see why he would give the pages and Dagger to a stranger , unless they were KGC also
Well good luck Hope this gave you some ideas on how to approach the matter, Snows melting here