Key8

And for those who are interested why this is the way it is

Edelweiss runs on its own IT platform which cannot handle standard IATA tickets
Travel agencies book bulk quotas on the flight and will only transfer the names of their clients a few days before the flight to Edelweiss.
At that time they match the names in the seat reservations with the passenger list.

If you need a connecting flight or a flight starting outside Switzerland you need to book it with Swiss, a IATA ticket will issued and handled by Swiss
(That's why you need checkin in with Swiss sometimes, depending on the airport).
I think the procdure Swiss applies it that again it only transfers the names of passengers to Edelweiss and they match that with the seat reservations a couple of days before the flight..

That is why
a) You cannot choose your seats on Swiss.com for a flight operated by Edelweis
b) You cannot use the Swiss Record locator (or ticket number) with Edelweiss - as they will have no record at that time you book
c) You do not have an Edelweiss reservations number (you will get one once you have actually have made a seat reservation because then you are in their system)

The only question I have for the real pros here: Eco seat reservations need to be paid - so I think no one would just make dummy bookings. I wonder however what happens if you just made a business seat booking without having a ticket - which is possible in first instance - the risk of fate booking is quite high... wonder how they keep this under controll

The different IT btw also explains that their call center is completely separate from the LH/Swiss universe. The agents sit in South Africa but there are only so few of it that I often end up on the same and start knowing them by name...