Out of the six 1904 series of Pre-Designs, only Project I was equipped with 28cm calibre main guns the rest were all 30,5cm in various numbers, which shows the preference of the larger calibre weapons by Siegfried Popper.
The series shows that Popper and the team of the MTK wished to stay below 13.000tons hence the how the main Guns number increase or decrease the secondary gun numbers accordingly decreases or increases in number accordingly. Here for example 4 casemated 19cm Guns were sacrificed for increasing the main gun calibre to 30,5cm. Another unique about these designs are the introduction of the 30,5cm Guns but not the final 45 calibre ones but a shorter 40 ones which seems consistent of an incremental increase in firepower over the previous class. Also this was the only design to have 19knots speed with 16.000shp engine power to reach it, rather 18.000 of the previous class and 20.000 of the final one.
The design had the following characteristics:
Dimensions: Unknown except the width so I've used the data of the Radetzkys: 137,5m (wl) 138,8m (oa) x 24,0m x 8,1m
Displacement: 12.200tons (standard)
Armour: 40mm Deck, 230mm Belt
Engines: 16.000shp Yarrow Vertical Triple Expansion Engines, 2 Shafts
Speed: 35km/h (19knots)
Range: 7.400km at 18,5km/h (4.000nm at 10knots)
Armaments:
2x2 30,5cm/40 Skoda K05 Cannons
4x2 19cm/42 Skoda K03 Guns
10x1 7cm/50 Skoda K10 Guns
3x1 45cm Underwater Torpedo tubes
The only known data table about the 1904 projects:
https://i.imgur.com/sHhBwgy.jpg