In the case of most breeds, you generally are buying a pure-breed. Rhode Island Reds can sometimes be different, though, as many hatchery RIRs have New Hampshire Red/other breed ancestors. It just depends; some hatcheries care about keeping their breeding lines pure, and others just want egg production and sales. Most hatcheries do not sell that show-quality of birds, so yes, your Welsummer is probably just a better than average quality hatchery bird. Most feed stores get their chicks from hatcheries, but others get theirs from local breeders. I suppose you'll just have to ask. Do you have any photos to share of your birds? Its always so nice to see other peoples' chickens.