I am looking at a BLE in Scotland by Scottish maker named William Horton. I can find very little about him and the quality of his work. It does look to be in very good shape it has a polygraph lever systems and adjustable trigger system.
Can anyone shed some light on this for me?

You see I am stuck between 2 guns as there is a Cogswell & Harrison Sidelock from 1905 that I a looking at also.