The Dragon belonged to his father and my friend had no use for it, so he offered it to me and I gladly accepted.
Along with it, I got several boxes of electronic components and looking at one of them that was in my storage place, and now knowing what I'm looking at

The lower part of the 16KB eprom is almost identical to regular SuperDOS E6 but for a couple of translated string and two bytes, and then there's the upper part which is filled up to almost 12KB.
I don't know if it's an original or modified rom, but the startup messages show it's from 1987, which is quite late in the Dragons' life.
To try it on XRoar I had to rename it to one of the standard roms, as otherwise it's executed like a regular cartridge and the rom seems to freeze probably waiting an answer from the FDC.
And without further ado, here you have the rom file and some screenshots!
Cheers,
Rob