TimeLine window pulldowns work sorta (for the options that were coded :) Still trying to bring back code without recoding uiDefButs. In future these will get directly operator stuff linked. For time being made a simple operator call function, like: WM_operator_call(C, "ED_MARKER_OT_add"); and for forcing operator to run in the main region-window: WM_operator_call_rwin(C, "ED_MARKER_OT_add"); These calls also work for modal operators, like marker grab in this case.