Hi Dan, I can't help you out but I will soon find myself in a similar situation soon, looking at couple of places a little further down river. I live in Nyack right now and would love to meet up for coffee and chat with someone at the same stage.
One piece of advice from someone who really doesn't have the experience to give it, but here it is anyway: if you're looking to capitalize on the historic aspect, try asking historical societies in the area. I used to work in historic richmondtown in Staten Island and they had a lot of experience with contractors hired to maintain or repair the homes, some of which were four hundred years old. For instance, whoever is in charge of the many historic homes on this list in Beacon must have someone they trust to maintain them: https://en.wikipedia.org/wiki/National_Register_of_Historic_Places_listings_in_Dutchess_County,_New_York
