Cushings hair wouldn't be bright, shiny and healthy looking.
It would be rough in combination with being dull looking and wavy with a failure to shed.
I believe him to be borderline Cushings, as he is 29 years old.
His coat is mostly shiny, but the 'ever shedding' hairs are dull in appearance.
As well, his winter coat is where I truly see the wavy hairs.
His winter coat is 3x the coat he had, ie. THICK (in winter) in his younger days.