Personally, I would regard adding a telescopic sight as sacrilegious. They spoil the lines of the rifle and usually reduce its value.
Telescopic sights are difficult to mount on an MS because of the split rear bridge and the high angle of the bolt handle when open. This means that the 'scopes are usually mounted far too high; which leads to additional problems: the stock is not made to allow the sight to be used, so it becomes awkward and in the wrong place (this does not apply to those later MS rifles with a 'pancake' cheek piece, which allows you to slide the cheek up and down the stock - Terry Weiland is very complimentary about this stock design in 'Great Hunting Rifles') and the sight and barrel are too far apart, which introduces difficulties with the zero.
Otherwise, I would echo the thoughts of BR (the great guru of Mannlichers) - if you are going to get a 'scope mounted, make the effort to get it done properly. Badly mounted ones look terrible.
The other people possibly worth talking to are
Daniel Fraser and C. H. Haygarth (both in Scotland), both Mannlicher specialists. Other highly competent gunsmiths would be Mark Crudgington
at
George Gibbs and
Lee Butler. Having said all that, the Dorleac mounts look a very good place to start and end.
