Wally,
a few points: I have very mixed feelings on your thread in here. Not only is this forum focusing on German K98k rifles, especially up to 1945, and you are asking on an Austrian WWI rifle, so your request is off the topic of this forum. Secondly, from my impression this forum is - at least to my understanding and from reading in here for a few years - on the discussion of genuine and "as-issued" rifles. This means, for the sniper section, that while indeed from time to time someone shows his reproduction sniper rifle, it still isn't the focus of this forum nor this forum section. At least personally I'm here to learn and see on German WWI and WWII sniper rifles (admittedly sometimes with items off, but with a certain context, such as foreign WWII sniper rifles, for example the M.39/43
@alund had posted very recently), but - at least in this forum section - not for giving tips on how to build "sniper rifles". Additionally you seem to ask more for a sporting rifle rather than to build a replica sniper rifle. Hence you might better in a rifle building forum than in this forum.
To nevertheless give you a reply to your request as well: note the Mannlicher 1895 uses en bloc clips. This means if you mount a scope overbore you have to take off the scope every time you reload it. This was the reason why Austrian in WWI used a scope mount that sets the scope off to the left. So you either have the choice to use an overbore mount with the requirement to take off the scope every time you load a clip (unless you anyway only hand load single rounds), or you have to find a scope mount that is offset to the left. All of that is the reason why there are no real aftermarket mounts for the Mannlicher 1895 rifle. Once there were quite expensive but also very well made reproduction mounts of the Austrian WWI scope mount available from Italy. They were expensive already back then, plus I have not seen a spare mount of those for years - only some faux rifles using this mount, but now advertised as original.
Also you were asking on which scope to use. Austria mainly had Kahles Mignon 4x scopes, as well as C. Reichert scopes. Aside of these two (I think they supplied over 60% of all scopes) you can also find hunter donated scopes, German supplied scopes of very distinctive manufacturers, and Süss Budapest scopes. The single tube scope of the Reichert and Kahles scopes required special skills when mounting them to the rings since the main tube was of a smaller diameter than the front and rear end; they developed rather unique fashions for those with wrapping like a band for the rear ring and later using split rings soldered as in between parts to the tube. Also note for the correct eye relief the rear scope ring is located in the place where the focal adjustment is sitting on commercial scopes of those, hence you can't even use a commercial scope but have to very specifically search for military scopes without focal adjustment. I though think this was not what you were asking upon, to build an exact replica?
Honestly spoken: I think you are better if you sell this rifle (or keep it as is) and buy any other milsurp rifle rather than to do something to this rifle that only burns money in expensive mounts and scopes that in the end you are not fully satisfied with is the better choice.