While waiting for answers or suggestions, I went on looking for information on the net, to solve the problem.
I understand that this cartridge format is the same of Auretta's cartridges of the seventies and now I am also sure there is no way to obtain new ones, because Aurora changed its format (that at present is Parker-like) and no one seems to produce such old cartridges.
At the end, If I would use the Alba Duplex pen, I was facing two choices:
- clean the old cartridges - the pen's case came with two of them whose ink inside has dried – and fill them with new ink using a syringe
- try to adapt a converter to fit the pen.
I was not confortable with the first solution, that would have made the pen a sort of eyedropper, so I went with the second choice.
I found out a couple of possible solutions, both based on reuse of old cartridges, and since in the meantime I bought another vintage Alba Duplex, I now have 4 old cartridges, so I tested both.
As preparatory step I had to found a converter that could slide into the Alba Duplex barrel, that is unexpectedly narrow inside and it does not allow those converters with the metal sleeve covering the piston worm a bit too large, to get inside.
I cut away the part of the cartridge that fits into pen's section:
And I finally fixed it on the converter, sliding the converter mouth into the small plastic cilinder:
To fix the two parts I tried three different glues: first an ordinary general purpose adhesive, that did not work; second a stronger glue, that appeared to adhere, but when I tried to ink the pen, I noticed copious ink leaks between the two joined parts of the converter; when I tried to remove it from the pen, the small plastic collar unstuck and remained inside pen's section.
At the end, I bought a poliethilene specific glue, that worked.
The original cartridge is not an unique piece, but it is made of three parts: the body, a bottom stopper and a rather complicated manifold (hope the English term is correct), that couples the cartridge with the section:
The old cartridge manifold has two walls on the back part so that the body slips between the two.
I removed the internal one to allow a full run of the converter piston.
I grabbed another converter, with the same properties I indicated above and I removed the converter's manifold:
Then I fixed the converter inside cartridge manifold, using the polyethilene glue:
This second solution seems to work better that the first one, where original converter mouth may cover pen feeder inlet, not allowing a correct ink flow – infact the pen goes into starvation after a while, forcing me to act on the converter knob to push some ink into the feeder.
I am stil testing the second solution at work: at the moment I have not had problems in ink feeding.