Snautzer, each aircraft had its own electrical wiring diagram with codes for the different electrical equipment. There was no rule amongst aircraft industry that a code would only be issued for one particular aircraft type, but it was rather by chance that codes like V23 were not used by other aircraft types. This now helps identify the aircraft type these sticks belonged to.
The Fw 190 typically had V60 (I say typically, because there were some late war variants with autopilot that had a different code for the control stick, 1V43). It typically had a KG 13B, but exceptions are known (KG 13A, and in late production KG 13C)
The Bf 109 G typically had V23 (see
http://germancontrolsticks.blogspot....Bf%20109%20G-6). It typically had a KG 13A, but exceptions are known.
I haven't come across one with V25, but that doesn't mean it didn't exist. The color (red), placement (large V-number around the base) and type (B1-Kn.) of marking on your stick is typical for a Bf 109 stick and I'd bet it came from a 109 if it is an original marking.
B1-Kn. stood for B1-Knopf, which was the button at the top. The trigger was called A-Knopf and the button on the top left B2-Knopf.
Cheers,
Roger