I previously wrote about him here.
Today, I comment regarding which details of his pure Steampunk paintings are Steampunk, and which are true to the 19th century world used as his setting. Also noted are a few of his Steampunk shape sources.
The steam-powered airships are pure Steampunk: engineering impossibilities. The ships, however, are similar to 1890s French armored cruisers.
Voitekhovitch borrowed the prow and military masts of this vintage cruiser.
The "tumblehome" side profile is more from this vintage battleship that also has some impressive military (weaponized) masts.
Note the elevated railroad. The locomotive is derived from mid-1800s Crampton types having huge driving wheels. The omnibuses on the street are horse-drawn, not Steampunk like the airship.
Example of a Crampton type locomotive.
The main Leipzig marketplace as it appeared around 1900, but with the addition of an airship that's apparently not steam-powered.
The cars appear to be 1915 vintage, but perhaps powered by liquid gas (note the copper tanks at the rear of the car at the right).
A steam-powered vehicle in the foreground plus the usual airships.
Probably not the best translation. The tram and cart seem steam-powered, but there's also a horse-drawn carriage at the left. As is usual in Voitekhovitch's paintings, all this including the airships is normal environment for the people depicted.
Everything else seems pure-1890.