Ok, hereĀ“s som pictures of the reservoir:
From top:
Size comparison:
The pump, a Maxi-Jet 1000, is a space-saving direct-mount to the reservoir, witch are made of 5mm plexi.
The filler-cap are made from a plastic coke-bottle, and glued to the top with cyanoacrylate.
Feel free to ask for more pictures and details!