Hi Cem,

There exist in total 8 booklets; you can still order two of them directly from the Märklin spare part center or via your preferred dealer(*).

Part numbers are #600181 and #600188; price even by Märklin is only 2,25€ each (i.e. PG04).

In detail they are as follows:

User guide 1 - #683670
User guide 2 - #600181 (*)
User guide 3 - #600172 (loco)
User guide 4 - #600188 (*)
Supplement 1 - #683690
Supplement 2 - #600391
Supplement 3 - #600173
Supplement 4 - #600392

Default addresses of the digital set version #2681 are 10 (loco, German emperor) and 11 (empress). Lights of the two compositions consisting of each 3 electric connected cars can then be switches using f1-f3 (f1=left car, f2 royal car with center rail shoe, f3 right car).