My replacement tiebars arrived. I replaced them according to the instructions given in the FxBricks-Blog of November 10th. However, after replacing the tiebars the switch-rails are out of power (only the switch rails are powerless, all non-moveable rails are powered correctly). Perhaps I damaged the thin metal/foil on the underside of the switch rail (it looks slightly deformed), although I proceeded with utmost care. Anybody else experiencing similar problems?
EDIT: I found the problem. The foil-thin metal on the underside of the switch rails was bent down (see image, bending indicated with a blue line). After carefuly bending it into an even position it works and both switch rails have power!