I don't know where you can find chapter and verse on this, but I have dismantled a couple of these in my time, and it's pretty straightforward and there are no unpleasant surprises. It is very similar to the Haenel 28 single shot. As I recall, you unscrew the magazine tube and cylinder end cap, remove grip plates, disengage cocking lever, slide out the piston in the usual way. As the barrel and cylinder are one unit all you are then left with is to is remove the vertically sliding breech plate by removing the relevant screws. As long as you make a note of what you do as you go along, you will have no problem reassembling it in the reverse order.
The main problem with these pistols, like most repeaters, is jamming. It is fatal to use waisted pellets, as the breech plate at best chops them in half, or at worst jams tight. Freeing up a jammed breech plate is tedious. Even lead ball can be unpredictable unless you get just the right consistent size.
Wheh it comes to loading, remember to put the round shot into the cylinder first and then carefully push home the spring loaded shot tube over these until it can be screwed in place. Any attempt to load the shot tube first and then fit it into the pistol will keep you occupied for many an interesting hour and turn the air blue.