I need an identification of the towed gun on the photo. Is a cylinder on the left of the barrel symply а case for swab or some kind of the antirecoil system?
I do not know if it is the same model, but it seems that Argentina had an offer of Nordenfelt (London) to use the barrel of guns Krupp 7.5 cm / L24,5 1884 model and modernize, using a carriage Maxim Nordenfelt 1896.
He offered a screw breech block Maxim Nordenfelt, who later became the Krupp selection to modify all previous models, and in a somewhat fake competition, won the same Krupp.-
Its braking and recoil system in the carriage (hydraulic and spring), was similar to those of rapid fire guns to the Argentine Navy. He also had a shield, which after almost all would use in WWI.-
The prototype is preserved at the Museum of Military College Nación.-
Which maintained the same breech block and the same brake recoil than its predecessor, but with a short barrel and a gun carriage mountain.-
In the Argentine Navy was used as landing cannon.-
The guns of the next picture have plates Maxim-Nordenfelt (or Vickers, Sons & Maxim) 75mm, Mod 1897, and came aboard gunboats "Parana" and "Rosario" in the year 1908.-
Foto MWAA de zonamilitar
They are preserved in the Naval “Base de Puerto Belgrano”.-
Remember them in the movie "Legionnaire", from Jean-Claude Van Damme?
The appearance of the Hotchkiss QF was a little different from the photo "Turkish (Osman) field gun of the beginning of the twentieth century", are higher , the cylinders of recoil / recuperators are shorter and thicker, and the movements, lifting and turning, are those of naval model. And the breech block is from vertical displacement.-
In the following pictures you see a 3pound (47mm) it should not have been very different to 6 pound (57mm) .