Nice, mine got the hole body. This is only the topplate listet on ebay. Im selling if any of you would like it!The second item Schloßeinsatz 2000/XIIIB2, Fl 50200 is also put up for sale on Ebay ...
Luftwaffe Schloßeinsatz 2000/XIIIB2, Fl 50200 | eBay
The werk nummer seems to be"Werk Nr. 60189/01-22780"
Also the line with the Wasser in the ID plate is "Kühlstoff" - cooling liquid. So I agree with Snautzer01 that's a part of a cooling system
The switch seems to be for a fan ( Gebläse ) - "Ein"- on and "Aus" - off
The cards with the Stern-Dreieck-Schalter ( star-delta switch ) and the Anschlusklemmen fur Erregermaschine - connection terminals for the exciter machine.