FWIW, about 15 years ago I had a perfectly serviceable Bemis toilet seat. It was original to the home, built in 1992 but the hinge broke. I called Bemis and they happily sent me another hinge.
Then about five years ago, of course one of the other identical toilet seats in the home had its hinge break as well. I called Bemis again expecting them to either send me or sell me another hinge for this one. This time they said they no longer supply any hinges for their toilet seats or hinge parts, for liability reasons. They told me if anything happens to their hinge you need to replace the entire seat.