I'd suggest you read this thread about coils
then ask your tuner to check and, if necessary, rectify the coils on the suspect notes during the tuning.
I discovered a problem with the seating of all my tenor and treble strings on the pressure bar immediately after my last tuning (as a result of the tuning in fact). Putting that right transformed the tone of the piano to what I had always wanted to be but put all the unisons out.
PS Hadn't noticed your new pictures before writing the above.
Underlying what Del says, if I have understood what he has written before, is that proper termination of the string is crucial. There are two elements to this: the shape of the V-bar together with the string's conformity to it, and the stability of the non-speaking length at the pressure bar, if there is one, and the coil.
Bluthner would have gone to great lengths to ensure good terminations before the piano left the factory.
The problem may be somewhere else entirely, as with Tomaz's Steinway, but it's worth looking into Del's hunch.