Keep in mind that many infilled shaft features, especially privies, were capped with a layer of clay, either when finally retired (fully filled in) or in between deposition episodes. The clay you are encountering may be a cap and the artifacts are below.
Polar Bear Tobacco is well known for being one of the companies who put 1909-11 T206 baseball cards (think the famous Honus Wagner card) in their products.
Just recycle the ones that people wouldn't want. Not EVERYTHING is collectable or savable. I know it seems sacrilege to people like us, but sometimes things just need to get tossed.
Historically, it has been. That is set to change in 2022, as a part of the stimulus bill specified that payment processors (like PayPal) now must issue 1099s after only a handful of transactions (versus 200 in the past) and/or $600 (versus $20,000 in the past)...