It is impossible to mount a scope LOW on a pre-1952 Mannlicher-Schoenauer , M 03, 05, 08, 10, 24, 25, 1950, without extensive alterations to the action. All these actions have clip guides at the front of the receiver bridge. As the bolt handle has to clear these clip guides, it raises fairly high. Additionally, the sole wing type safety must be turned under the scope. Even if the scope is mounted fairly high, there is very little space under the scope to do turn the wing. See Dorleac’s photo:

From 1952 on the Steyr factory left off the clip guides to allow a bolt handle forged lower. This allowed for a lower bolt handle lift and thus lower mounting of a scope. But as a low mounted scope made the standard wing safety inoperative, Steyr added an additional sear-blocking safety, side- first, later tang-.
Mike Bailey’s photos show a M1903 Greek military action heavily altered to allow for lower scope mounting: Clip guides removed from the receiver bridge and bolt handle rewelded closer to bolt body. A completely new, custom firing pin nut/safety design is installed instead of the classic Mannlicher wing safety. As the EAW side swing mounts are fairly high themselves, all these efforts still did not lead to a really low-mounted scope.

So if you want to avoid action alterations, raise the safety wing to an upright position. Then place a scope, parallel to action and bore, above the upright safety wing. This is about as low as you can mount that scope without excessive reworking of the M1903 Mannlicher-Schoenauer action.
Personally, I have Mannlicher-Schoenauers with These types of Mounts: M24 with the obsolete Vienna snap-on mount, M03 by Gibbs with an EAW side mount (similar to the G&H or Jaeger one), M25 and 03 with claw Mounts dovetailed into receiver ring, M10 and "Magnum" Action claw mounted with fron base ring mounted on barrel. I agree with Joel Dorleac: A claw mount is the only proper way to mount a scope on an early Mannlicher-Schoenauer.