Hmmmmm...........Many, many hours spent flying 'PZ with Intra Airways in the 70's. Procedures prior to the 1st flight of the day tested amongst other things prop-control and the electric feathering pump. Subsequent flights didn't, or maybe a mechanical pitch-control check if the pilot so wished. Mags we always checked before each flight.
When an engine failure occurred with the luxury of speed and altitude, the procedure was identify, throttle closed, button pressed, pitch fully coarse, mixture idle cut-off. Thus the electric pump only had to "finish off" the feathering of an already mechanically-coarsening prop.
However, the procedure with an engine failure IMMEDIATELY after take-off was identify, button pressed, mixture idle cut-off, leaving the crew to counter the swing, fly the aeroplane, get the gear up, and climb away. In this case the electric pump has to do ALL the work of changing the prop from fine to fully-feathered. IMHO this aircraft would have had no trouble climbing away with the stated load and a feathered prop, and no chance of sustaining flight with a windmilling prop in fine (takeoff) pitch on the dead engine. IF indeed the crew followed the above procedure, the position of No1 prop's pitch in the photograph would seem to point to a possible complete failure of No1 electric feathering pump.
I doubt the crew would have had the time or capacity to try the first procedure after realising that the second had not worked, and anyway it still would have resulted in a partially-feathered prop, and a whole load of drag.
Just my pennyworth................tough old bird, sad to see her like this.