Hi Roger

Disclaimer: I don't have this station (Stuttgart) in any form. I don't own the pictures displayed here.
Here is the little I know
- in the 1935 general catalogue there is a gauge O version and a gauge 1 version. The O version is referenced 2039G/O and is 83.5 cm long. The 1 version is referenced 2039G/1 and is 114 cm long.
- in the 1947 general catalogue there is an gauge OO version. It is referenced 2039G and is 83.5 cm long.

So it seems that Märklin did not try to hide it was the same Stuttgart station that was grossly undersized compared to the real thing.
The real Stuttgart station hosts 15 tracks perpendicularly (terminal station) and seems to be 190 m "long" (the facade on Arnulf Klett Platz).
So in HO it should have been 218 cm long
Here is the 1935 Märklin catalogue extract


Here is the 1947 Märklin catalogue page


Here is the real thing


Note: because of its large size, the whole station, suffixed G ("Gesamt" or whole)
The left part was 2038B and the right part was 2039B (B= Bahnhof)

I hope this helps

Jean

Hi Roger
Here, on ebay.de (Germany) there are 2 2039G/1 1 Gauge Stuttgart stations, one selling for €11 500 and another one for 3 850€ both open for downwards negociation.
Also to be found is the 2038B (left part of the O model) for 238€ but still 6 days to go upwards.
Cheers
Jean