I have a Nikko Stirling Diamond 10-50x60 scope. I bought this second hand and so do not know exactly how old it is. I am looking for a zoom lever for it. Rowan Engineering do one but it says on their site that it only fits the Mk 3 model. I have the box for the scope and it just calls it a10-55x60 MD which I understand means it is a mil dot version. Is there any way of determining if it is a Mk3 or what else it might be? The Rowan product isn't cheap( as you would expect) so I don't want to make a mistake! Also does anyone know where i might get some lense covers for this? I have even tried the importer and they say they can't get them.