Outside of Mr. Galazan's later guns, I don't believe there were ever any American guns produced with an intercepting sear sidelock.
That would seem to be the point of the exercise of building a sidelock, and one would want it to be of the quality of several of the English produced sidelocks, say, Brazier, Chilton, etc.
Calling a Tobin, among others, a sidelock, doesn't make it so.

Best,
Ted