You talking about these? They are not full stairs, just slant railings without the treads. Note too the stanchion needs to be installed into pre-drilled holes which are spaced properly. I've not found this sort of railing to be easily used.
If these are what you want, check with JADAR of Poland. IIRC, they are a subsidiary of Mirage of Poland and handle other Polish companies stuff.
My preferred photoetch inclined ladders are either Gold Medal Models, White Ensign, or L'Arsenal. They are ladders with side rails and treads. Fold up the side rails to a U-shape, then erect the stair treads to be parallel with the deck.