I was looking through my spares box and found the other bit of the arms that I had retained and realised that this was the bit that was holding the 'binoculars' . It also had the 'hand' from the other arm that went missing attached. So I trimmed off the rest of that hand and sanded things down. I then removed the arm from a French mounted general and fixed the new arm on. Not too bad and since I don't need hundreds a worthwhile one off.
Now if only I could think of Officer on foot that would make a reasonable conversion?
His Prussian counterpart using both hands to use his binoculars and mounted on an S range horse this time..