This thread is still running and running I see !
I go back to what I suggested earlier (or maybe two of my suggestions) ... as several other people are repeating and re-repeatng !
1) trompe l'oeil would explain the far end ... the whole of that end wall could just be painted, doors and all ? When I was at school, back in the dark ages, I painted school play scenery ... and unfortunately cant find a photo of it ... but I remember painting columns for the set ... and it wasn't until I saw a photo of the set after the play was finished, that I realised I had got the shadows wrong on columns.
2) the two side doors couldn't be opened towards us ... but they could be opened away from us ... and I go back to what I suggested earlier that this end wall reminds me of the screen in an Orthodox church, where the side doors open away, and into the sanctuary (there would also have to be a central door, but that could be hidden behind the central part if that section is painted on a board ?)
This rather poor photo shows what I mean ? The left and centre doors are obvious; the right hand door in the iconostasis is somewhat hidden behind the epitafia ?