Here's the sights Martin. The 'wings' are higher and steeper than I like but OK, for now. I think I'll browse some internet sights and see if I can find a 2 leaf (3 sights including the point blank sight) that can be dovetailed into the rear rib. The hold-down screw will have to be sunk a bit deeper, but that's not a problem unless the base is hollow, which I don't think is the case. If all else fails, there are some double sights at Trackofthewolf site that will work - standing plus one flip-up blade. Of course, they have to be filed for zero - but that's all part and parcel of sight replacement.

regardless of the weather, I'm going to try it out today. Notice the adjustable elevator has been removed from the rear sight, but the screws are installed to fill the holes. Laying the sight over, reduces the height a bit for close shots, using the screw heads to indicate the centre of the sight. This may give a good sight for point blank shooting, giving this system 2 sights on the rear flip-up sight, plus a longer range sight using the front sight. I'll test it out today - minus 25 wind chill forecast - it won't be a long day at the range, I'll wager.