I once saw a Stevens O/U .410 which appeared to be based on the regular Stevens single with a small hump atop the frame for the upper bbl. It had two Thin hammers which fit thecenter slot for the regular hammer & two triggers for firing them.
Operating strictly from memory here but seem to recall a model # of 240, though this could be wrong.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra