Dear Scotty,  The reason you're having problems tuning the Coinola K
is because at the time of its manufacture the standard tuning pitch
was A=435 Hz.  I am quite sure if you re-tune it to A=435 that this
would rectify your dilemma.

I had heard of someone who attempted to tune a Violano Virtuoso to
A=440, only to fracture the piano harp (disaster!).

Hope this helps,
D.F. Rowe
Bronx, New York