Xausa, the changeover from the "old" Mannlicher – Schoenauer bolt stop to the "new" one did not depend on production year, but on model. All the short magazine models, the Mannlichers M 92, M 93, M 95 as well as the Mannlicher – Schoenauers M 1900, M 03, M 05, M 08 and M 10 had the same "old style" bolt stop, inherited from the German M88 commission rifle. These models were built unchanged til WW2.
The photo shows the "old style" on my M1900, bottom, and the "new" one on my M1924, top.

The old bolt stop has the hinge in the middle, the bolt stop proper at the front end and a coil spring under the actuating "button" at the rear.
When the Steyr people decided to adapt the Mannlicher – Schoenauer action to longer cartridges like the 30-06 with the model 1924, they had to lengthen the magazine by 6.4 mm. Instead of redesigning the complete rifle, they left receiver and bolt the same length. Remember, all turn –bolt Mannlichers and Mannlicher – Schoenauers have the same receiver and bolt length, inherited from the M88, from the M92 to the last "Magnum" models of the 1970s. For the different magazine lengths see this thread:
http://forums.nitroexpress.com/showflat.php?Cat=0&Number=122479&an=0&page=2#Post122479
They decided to merely set the rear wall of the magazine farther back on the receiver and to lengthen the bolt travel accordingly. This required a slight change to the trigger mechanism, a shorter sear lever, but led to a serious problem with the old style bolt stop: As the hole in the receiver wall and the hinge were now 6.4mm = .25" farther to the rear, an old style bolt stop's button and it's spring would now hang out in the air at the rear end of the receiver. So they designed the new bolt stop with the spring inside the housing in front of hinge and stop.
This new bolt stop was used on the .30-06 "Sequoya" M24, the M25 in several chamberings as well as on all post – war Mannlicher – Schoenauers.