Property encroachment issue

[Nat C.]

I am scheduled to close on a property this week. There are 2 buildings on the lot and the rear building is over 2000sq ft. I was at my friends house (a real estate broker) and he was looking up the property records.

He noticed that the property appears to be on neighbors land in the aerial view. I am including the map for all to see. This building was built in 1936. I am ordering an urgent land survey. My gut feeling is that the building will turn out to be encroaching on the back neighbors property.

The neighbors property was built in 1956 and the current owner has owned it since 1976. 

My broker friend says that the building I am buying will need to be torn down if it's encroaching. I think I could also possible ask to buy the additional slither of land from the back neighbor?

I am already getting a good deal on this property but I'm thinking I should possibly go back to the seller and try to negotiate a lower price if the survey comes back showing an encroachment.

Has anyone ever had any similar issues like this? Any suggestions for young Natalie?