In the book of my old friend Bob Brooker, "British Military pistols and associated edged weapons" there are published five Scottish all steel flintlock pistols which possibly have been made for Scottish yeomanry or militia troops. All these pistols but one show no view and proof marks on their barfrels and have a rather resemblance with the pair in question.

Thank you Udo for your knowledge and research. It brings me one step closer to understanding this pistols. I know you know pistols and therfore I appriciate your inputs :)