These are birds I got from a local silkie breeder in nc. One I purchased as a chick and the other I hatched from his eggs. They are all black w green iridescent feathering and a top hat and no apparent combs. Well i can't find the pic of the smaller on I hatched but they are basically twins.
Personally, I feel they are Satin Silkies.
Neither of the birds in question have a body shape that doesn't meet that of Silkies. If they were crosses, I would expect lighter skin, possibly smaller crests and a different body shape.