Clean gear shows respect for the whole process.

The phrase "waste time" really depends. Your question made me remember a box of my grandma's old fabric scraps I almost tossed. They looked like faded rags, but I shook them out and found these amazing old quilt pieces sewn together inside. It was a total surprise. Like what amy_lopez80 said about soaking to revive colors, sometimes you just have to look at old stuff a different way. I'm glad I didn't just dump the whole box.

The law here in the UK is you have to report finds like that under the Treasure Act. Call your local finds liaison officer, they're used to this. They'll help get it recorded and valued, and a museum might buy it. You'd then split the reward with the landowner if that's not you. It feels wrong to just put it in a drawer, and doing it right is simpler than you think. I had a friend go through this and the process was very clear.

Disagree with @bethyoung, finding history beats dust.