I have tried the "spring" method to "restore crown" on an old upt. It worked! The piano sounded much better after the addition of the springs. I think I put 5 of them behind the treble bridge. A lady got rid of her Wurlitzer grand to buy this piano from me. We're not talking high quality instruments here, but you never know what might help until you try. You could try this on any piano and reverse it by simply removing the springs. Lew Herwig told me what kind of valve spring to buy. I think it was some model of Ford truck. When I went to the automotive parts store, they didn't have that spring in stock, but the guy let me rummage around his valve spring supply and I picked something that looked feasible. It turned out that I would have preferred a stiffer spring. I tightened the springs up all the way. Everything is intact 5 years later. There is an article on "valve spring surgery" in an issue of PTJ from the 60's. It could be tracked down in the Journal index if anyone is interested. Bob Anderson Tucson, AZ
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