LOL!
The display cupboard looks identical. What a co-incidence! 
I bought mine (I have two of them) some time ago in a DIY store called "toom". If I remember correctly it was about 20 EUR each.
Aha! So, the doors are made from tic tac box plastic!
(I really should have read your description on your website before asking questions. 
)
Yes, that's the reason why I put the text "More information on this item [...]" at the top of this thread
how did you mount the playmo-display to the SysX-wall?
I put a little bit of blue-tac on the back, very thin and "glued" it to the wall. (actually I'm using the German equivalent of blue-tac from Pritt or Uhu, but I must admit, that currently I do not know how it's named and it's to late to walk to the basement and have a look
)
how did you fix the tictac-glass-doors to the display?
Untill yesterday I just placed the glass doors loose inside the cupboard. The photo (cf. top) is a little bit "faked" because Little Jo holds the right opened door in place so that it can not be seen, that it is just loose.
Yesterday I put on each side, where in real live the hinge is, a small drop superglue (Sekundenkleber) on the top and bottom of the glass. This was right enough so that now the glasses are "fixed" stuck inside the cupboard body and still can be moved around this "hinge" (similiar mechanism like with cupboard doors of other real Playmobil items) ... don't know if you understand what I mean (maybe somebody understanding can explain it better).
