Good post Gregory. If by any chance you receive any follow-up information from the pros, please let us know! Take care.
From I Phone GHI Greg’s Home Inspections, LLC Serving DC MD and VA
Likely refractory cement.
The damper body is corroded. If there is a smoke shelf the issue is multiplied.
Not enough information.
Image of the chimney, crown, and fireplace e please.
Certified WETT inspector.