Counterfeit 1876-S And 1804 Dollars

I posted on this forum years ago, but I've since sold off most of my collection. My father-in-law recently lent me two coins he likes to talk about. He's had them for decades. I immediately thought they were both counterfeit. Although I'm not familiar with the finer details of these coins, both are non-magnetic. I was surprised at the general quality of the 1876S; I can't see any bubbles, it's 38.1 mm, the denticles look good (the photo shows a bit of dirt in some areas of the denticles and lettering, and the bottom of the "8" on 1804 looks fine to me but not in the photo). The 1876S looks washed out a bit, but the big giveaway is the weight of 24.75 grams (more than 2 g light), and the coin is clearly not 90% silver -- in either appearance or when compared to the ping of a real 90% coin. Somewhat more surprising, to me, is the 1804 "dollar" coin, which is all wrong: it's also 38.1 mm, is only 20.65 grams (way too light), and is obviously copper. Not to mention that they intentionally made it looked heavily worn. It begs the question of why bother, and who would be fooled by something so off the mark -- but my father-in-law got it somehow.... Anyway, just posting for your entertainment value.