Plage i Laśkiewicz works proposed first a floatplane variant F.VIIW of a licence-built bomber (developed from a passenger plane) Fokker F.VII, but it was not built.
Then Plage i Laśkiewicz proposed quite modern twin-engined plane Lublin R-XX, the main designer of which was Jerzy Rudlicki.
The design was found satisfactory, but it had also faults, like moving of centre of gravity during flight and low fuselage rigidity.
The Polish Navy ordered 6 production aircraft in the beginning of 1935, with planned deliveries by April 1937, and Plage i Laśkiewicz prepared to build the R-XXA prototype.
However, the factory at that time was about to bankrupt (caused by a policy of Ministry of Defence, refusing to buy Lublin R-XIIIf planes), and on 23 November 1935 the Navy Headquarters broke off an order for R-XXA due to long development.
However, its development was soon canceled in mid-1936, because the factory proposed a floatplane variant LWS-5 of slightly more modern LWS-6 Żubr bomber.
This design was not completed as well, and the Polish Navy remained without torpedo bombers (there were finally ordered six CANT Z.506 in Italy, but only one unarmed was delivered by the outbreak of the war).
Armament: four 7.9 mm Vickers F machine guns on ring mountings in fuselage nose and in a dorsal position.