Hey navydevildoc,
Was the carb you removed from your Rover an old Solex? Series II and early IIAs came equipped with Solex carbs that had a throttle arm that moved up when depressing the accelerator pedal. When converting to a new Weber (whose arm is pulled down) in addition to installing the adapter base http://www.roversnorth.com/store/p-6...nith-carb.aspx you also need to change the bellcrank http://www.roversnorth.com/store/p-1...s-iia-iii.aspx in order to change the direction that the arm moves.
Hope this helps....I'll be online for awhile tonight if you have any additional questions.
Arthur Patsouris
Sales Manager
Rovers North, Inc.