We bought Behr brand Ash/brown masonry stain,  (because my husband is against painting bricks).

Maybe a couple stained glass windows.

Also, the appliances look older (dishwasher & stove) and I can see grease stains from your pictures underneath the vent hood.

Upstairs carpet is heavily stained and may need to be replaced. 

We have a water stain on the ceiling from when an upstairs toilet was clogged and it was running and eventually flooded through the floor. 

If you look at the condition of mortar and bricks and see anything that looks loose or missing you need some repointing/repairing at the least.Outside- could be water entering the structure between the chimney and the roof framing through holes in the flashing.If you have water stains coming out from the ash door you Most likely have water entering in to the chimney through the masonry.

We put everything new except one iron-cast tub, one toilet and the floors in the living areas and rooms (we sanded and stained the floors).

Be attentive to any staining or cracking of drywall.

Broken this, stained that, scratched this, and cracked that.

Lastly, we painted the concrete floors with KILZ stain and odor blocker.