It has predominantly kings and nobles, and airships are a big part of nearly all fantastical/anacronistic industrial revolution depictions. It's...damn near universal.
Politically, it's nothing like the 1920s or 30s, and a great deal like the early to mid 1800s in some places, more like the mid 15th in others.
Politics is much more important than what tech exists. People don't live like the 1920's in Eberron. There aren't tractors. Nothing like cars are commonplace. Sending stations are vastly more like telegraph services than even early telephones. Teleportation never existed in the real world, but it's an expensive luxury form of travel in Eberron, like chartering a fancy private jet. Trains and steam power in general, and thus machine automation, existed during the industrial revolution, as did the telegraph.
The point being, Eberron is not psuedo-any given decade. It's it's own thing, that has as much industrial revolutions and post-7 years war elements as it does turn of the 20th century elements.