Ok, Aaron - I'll have a go. (Quickly, because it's quite late here and I want to go to bed.)
The most important thing to check with a Mannlicher is the barrel throat for cordite 'burn' (erosion). If a rifle has this, walk away. The 'scope fittings and 'scope are irrelevant, and ought to detract from the value: the split rear bridge makes fitting mounts an ugly business, and they are usually too high because of the bolt throw.
The ideal Mannlicher ought to have two triggers, the rear being the set or 'hair' trigger, and be in the carbine ('stutzen') version. 6.5x54 is the ideal calibre. The rifle can be used like a shotgun.
The second rifle that you link to looks interesting. It looks to have been poorly re-blued, perhaps with boot polish. I imagine that the cleaning rod, which ought to be housed in the stock, has long since disappeared: don't worry, most of them have. I can't remember - and am too tired to check - whether the tang ('shotgun') safety is original or not - some models had them, some didn't - it is slightly ringing alarm bells.
Price (CAN$1,900) is not too bad. In the UK, this would be a low to fair price. Remember to check the barrel.
To offer opinion:
Advice regarding 'Cordite burn' seems wise for any arms of the early 'Nitro Express' period that may have been fed such.
Here are mid 1930s ICI loads for 6.5X54MS:
British proof on MS:
While a Mannlicher Schoenauer with mountings yet without 'scope or cuts / holes for mounts yet no mounts or 'scope is often somewhat devalued, those with properly mounted and regulated period 'scopes are valued at a premium by many.
It is worthy to note, however, that mountings which include 'dovetail' cuts to the receiver ring are considered to be inferior to those 'saddle mounted'.
The mounting shown on the $1900 rifle is a 'Vienna Snapper' as shown in the 1939 Stoeger.
They were usually installed / sighted by craftsmen at guild shops in the Steyr area:
Mannlicher Schoenauer rifles and stutzen were all offered with single (two stage) or double set triggers. Which is 'ideal' would depend on shooter preference / circumstance and the trigger assemblies were interchangeable.
1954 Stoeger:
All original, unaltered, M1903 (as well as M1900, Y1903, Y1903/14, Y1903/14/27 'Breda', and 'System 1930') Mannlicher Schoenauers were chambered for the 6.5X54MS.
More on the '$1900' MS:
-Stutzen (full stocked carbine) model.
- The tang safety is not original, yet appears to be tastefully and expertly done.
- Original style scope case is a nice bonus.
- _'Oesterr, Waffenfabr.- Ges. Steyr'_ indicates receiver made no later than 1926.
Stock on $1600 rifle may not be original or could be original 'custom order'? Schnabel forend is unusual and wrist seems a bit 'off' to me.
- 'Made in Austria'_ on bridge indicates receiver made 1924 or later.
- _'Oesterr, Waffenfabr.- Ges. Steyr'_ indicates receiver made no later than 1926.
- Rifle is not cut or drilled for 'scope, a 'plus' for originality.
1939 Stoeger: