I "kind of" solved it this way. I drilled 2 long holes into the top for 2 long alu rods, and connected the with a piece of wood. On that piece, I made a sledge, that holds a bolt with a top that fit a neck curvature. The bolt is grinded flat on top, and screwed onto a piece of heavy plastic, (could be wood). The pieces are covered with felt. The sledge has one bolt for adjusting both hight and sidewards position. The whole arrangement can be slided out, so it extends my work area. This makes any operation much more safe.
