Buying a 110 year old home w/ additional STR and LTR living areas

[Grant Med]

Hey everyone! My wife and I are moving to Louisiana and we have been presented with an offer that we are seriously considering. The main home in which we will be living in is 110 years old and has been beautifully maintained. The home includes a private entrance living quarters attached to the home (includes full kitchen, washer and dryer, wet bar, 2 walk in closets, etc.). There is also a separate small cottage in the backyard that is rent ready as well and it's currently being used as an STR. Obviously there is a ton of potential for income streams with this property but here are my questions:
1. Does anyone have experience with older homes and the associated costs to truly maintain them?

2. What questions would you ask the seller to best CYA to truly know if it's a good investment?

3. On average, how likely are sellers willing to disclose utility bills for the past year? (No separate meters for the 3 living areas)

We are already owners of a much newer rental property so this is definitely a much more involved decision.

Thank you!