Worth salvaging down from quality but old heirloom down blanket?

I have a high quality heirloom down blanket. Each square baffle has at least 4 in. loft and the down is most likely Polish down, which tends to be high quality. The blanket is about 60 years old, but was stored uncompressed when not used, and when used, used inside a comforter, so it’s in excellent condition. The blanket isn’t really used anymore because it’s sooooo warm, way too warm for US indoor use, even with the thermostat not turned up high.

How long can down last in good shape if stored uncompressed and dry? Do you think it’s worth using some of this down to augment any down quilts, pants or jackets? I guess that depends on the fill power, which may be difficult to measure accurately based on a thread I read here.

If it doesn’t have a musty smell to it, I could imagine it still being good.  I’ve got some 40-year-old down items that are still useable.

Yeah, could you sort it on a small scale to get the feathers out?  Got it from 400 FP to 600 FP, maybe?  Painter’s plastic sheeting and lots of tape to create one chamber with cross-flow wind at the top, blowing the lightest stuff into another settling chamber – a chamber that maybe has air exhausted from it after going through a pillow case.

Do you mean an heirloom quilt? If so, it could be worth a lot of money, so you might look into that before you pull it apart. We had one in the family, turned out to be appraised much higher than anyone expected.