A friend sent me an email recently. Had a guitar he hadn't played for a long time. Left it in his basement for a couple of decades. Dug it out last week and took it to a guitar shop. Was told it would cost $150-$200 to restore it to playable state. That's about what the guitar cost when it was new. For some reason he was surprised...
I am reminded of the old motorcycles that periodically emerge under a haystack where they'd been left in some barn. Now rusty, with corroded metal that has frozen the cylinders, and electrical cables eaten by mice, leather and rubber bits falling apart, batteries gummy with age. Treasures for those who have the knack (and money) for restoration, but for the rest of us, they're garage sculptures.
You left a ukulele under a "pile of newspapers" as in a fire trap of old papers piled on top of a delicate musical instrument for what seems to have been several years? A pile of paper hungrily sucking the moisture out of the wood for years while pressing down on the the neck, body and bridge to possibly deform them? And for some reason you're surprised it doesn't play well... I suspect your uke may become a wall hanger soon...