Hi Marek, unfortunately I was unable to find a replacement cable readily. And to be honest, I wasn't looking very hard then because we needed to replace the printer urgently. From what I saw of the internal wiring, replacing the cable would require me to further disassemble the printer. If you decide to do it, you should take photos and create a guide for it :)

The stupid plastic thingy seems to seve as a retaining wall for the cartridges. I'm not sure how "broken" your latch A is, but maybe you can try to glue the parts back with a few drops of cyanoacrylate glue. Or just leave it be since the printer is still working.