out of tune Wurlitzer

[Wimblees]

I have a problem that I hope some of you can help me with.

The piano is a 30 year old Wurlitzer console.  It sits on an inside wall, away
from heat vents and outside doors, no fire place in the room, away from the
kitchen, the washing machine is in the basement on the other side of the
house. It gets played about 3 hours a week by "a little old lady", no banging.

I have been tuning it twice a year for almost 20 years. For the last 3 years,
however, whenever I tuned it, it was very badly out of tune. I tuned it again
today, and the middle of the piano was almost 50 cents flat. What is so wierd
is that there are five notes with double wound strings on the treble bridge.
These notes were about 25 cetns flat. But the first note with plain strings
was about 50 cents flat. The rest of the trebel was comparably flat, but it
was better higher up. Even the top octave was flat. On the other hand, the
first octave was on pitch, but got flat closer to the trebel break, with the
last bass string only 10 cents flat. 

The soundboard an bridges and all seem tight, no cracks or seperations. This
has a soundbaord with the grain running from left to right. I though about a
cracked plate, but other signs of one are not there, namely action problems,
or damper problems. I checked for the pin block seperation, and although there
is a veneer cover on top of the piano, I cannot see any signs of seperation.
The back posts are all tight, with no seperation any where. 

Any thoughts, ideas, suggestions?

Happy Holidays

Willem Blees RPT
St. Louis.