We're back; got log in issue sorted.

Here are pages 50, 51, 52 of the 1939 Stoeger Catalog:

Detail of Take Down Model trigger guard and lever, pin parts:
Note part 14/1 which is for slotted tang of TD model to index. On other models receiver is held at rear with screw (part 71). Parts 49/2 and 49/3 are trigger guard catch and lever (TD Model only) which assemble to trigger guard with parts 49/4, 5, and 6. Parts 85, 86 comprise forend pin for TD model. Other models used forend screw (part 53) which also retained sling ring.

Images swiped from 'net:

Take Down trigger guard assembly.

This is part 14/1 from list above, but with 'special folding peep sight'.

Typical, original, Austrian proof marks on pre WW2 (and pre Anschluss) MS without clutter of additional marks. '411.08' indicates 411th arm to be 'nitro proofed' at Vienna in 1908, NPv is Vienna Nitro Proof, 4143 is MS serial number, C6.5 indicates cartridge (6,5X54, an M1903), and script EV (visible at underside of barrel and of receiver) is Austrian 'first proof'.

Typical Brit proofs on M1910 sold through British trade pre WW2.

From 1939 Stoeger.

British Proofs.

Mannlicher Schoenauer Take Down Model, cased.

In summary, It was proofed when new (Austria) 1920, sold through British retailer (proofed again), later reproofed in Germany.

If nothing is terribly wrong with it she's a very worthwhile project.

If it's a TD would be extra nice to restore that function, as well, though I don't ever recall seeing one with 20" barrel.

If it's a stutzen the tang appears to have been modified. Then again, Steyr was known to be accomodating to custom orders. A Take Down stutzen would seem redundant, though.