So, i put it to oof...
The inner race does not exist separately. It is machined into the hub itself, and the races pop in to that, then the outer races in turn pop in to those.
There is no separate baring complete, that presses into the hub.
Tell me I'm wrong. 
You're wrong.
The inner race often gets "left behind" on the stub shaft on removing the old bearing .. but must be removed.
Given the "right" kit a complete bearing can be pressed into the ABS ring that is really just a bearing carrier. Most places though sell the ABS ring/hub + bearing as a complete unit.
the bearing itself is shown as one of the portions of 24 here..VX don't sell it as a seperate item
http://opeloem.com/opel/omega_b_1994_2003/front_axle_and_suspension/front_hub.html
vx don't sell it as it doesn't exist. If it does I can't find it.
I should add we are talking about the same thing. The inner race that gets left on the hub has been removed. Both of them. Then there the barings with plastic cage thing.
With all that romeved that leaves what I called the inner race, as I'm working my way into the baring, if you see what I mean. ( actually the outer race from the centre)
As you say, item 24 shows the hub with reluctor ring built in. Between that and the stub axle there is what appears to be a baring. A complete baring. Where do we get this complete baring...?
Theres no sign of it on the web. There for I dont believe the complete baring exists. There for there is nothing to press in.