Buying a 86 year old home but has been recently updated

Hi guys,

I'm looking at a property in the new jersey area. It has good cash flow ($351 per mo) and is in a decent neighborhood (good middle /high schools). 

The rent updates are 

- (50 year) Roof -- assuming the roof should last 50 years?

- 4 yr old high efficiency a/c

However, the place is 93 years old. I read that houses typically live around 100 yr (+/-). financially it looks pretty solid with the cash flow but i'm scared to buy a house this old. Because of the house, walls and other parts breaking down. Am I over thinking this?

Thanks for your input!