I was testing out my new pak viewer/analyzer when I noticed that the passenger car for the Adler becomes available exactly ten years before its locomotive. Is this intended? The fact that it's exactly ten years make me suspect a typo. On the other hand, ten years before the Adler is very near the first passenger railway service, but there is no locomotive available in pak64 at that time, so the passenger car is useless for ten long years, even in game time.
There is a rocket available, by ravens early loco pak in the forum.
So it's set earlier to allow for unofficial add-ons, then. In that case, it would make more sense to set the date at September 1825 (Locomotion No. 1) rather than August. The freight cars should also have earlier introduction dates, because freight trains preceeded passenger trains. Or are the early freight cars too heavy for earlier locomotives, perhaps intended for some post-Adler add-on locomotives?
For a new player, that knows nothing of the large number of add-ons available, it will still look a bit strange that they can build passenger cars, but no locomotive to pull them.