My D/G Dony has got
Eb/F Bb/G# E/D Eb/F Bb/G#
This is almost the same as the one shown on the keyboards layout section of this site, except that the middle button has an E rather than an F, providing the "dutch" reversal on the half row. Yours has this as well, but split over the 2nd and 3rd button.
The essential difference between yours and mine seems to be that yours has lost the lowest accidentals (Eb/F) to make room for the high Eb/D. I can see that this would be a good way of doing things on a G/C where you are playing more in the top octave, or even on a 3 voice box, but it seems a bit unusual on a 2 voice D/G.
I don't know which of these is standard, or whether there is an fact a standard. Maybe the layouts relate to when the instruments were made, or maybe they just do them in a variety of ways.
I bought mine straight off the shelf in an accordion shop in Wadebridge (before it became Hobgoblin!), and at the time I had no idea what to do with the half row, or the extra basses for that matter...it was just a beautiful sounding box. It turned out, though, that I really liked the layout as it gives you all the accidentals just where you need them, you have an F natural in both octaves which is really useful, and I use that E/D reversal so much that I really miss it on a 2 row.