Door locks on historic home?

does anyone know if there is a deadbolt available that would work on a flat slab door…currently the doors have deadbolts that mount on back of the door (rim deadbolt)

Not without putting the striker holes in the door and jam.

If they currently have deadbolts, you could look and see if one of the slip over actuator locks will work. This style has a piece that fits over the existing deadbolt turn piece and literally just turns it.

The Danalock zwave version is compatible with smartthings but unfortunately doesn’t get very good reviews.

The August lock gets much better reviews but is not currently compatible with SmartThings.

Anyway, it’s something you might look into as a possibility.