Chimney repair for old unused flue
I've had two masonry contractors out.  They both agreed the flue  is unused, both stated  it is a dummy flue. I'm not convinced, but it doesn't matter. 

Both noted the water getting inside.  Booth discussed the cream of the crop solution,  New crown.  Neither oversold it. 

One liked the idea of metal cap,  one never heard of it,  lol. 

Both suggested to cementing cap the dummy flue and sealing cracks. As I know I'll never use this flue,  it made enough sense, I went this approach. 

Job done as it was the simplest most immediate solution.  I suspect in the near future,  maybe next season,  I will do a stainless,  or all out copper top,  with a drip edge,  as its astute top lady longer than concrete in wet snowy buffalo weather.