Early TR4s had a domed glass similiar to the 3As. At about CT11000 the flat glass / half exposed needle was introduced. So these are from a late TR4 or any TR4A. The Lucas ammeter should have the month and year of manufacture stamped on the side of the case. As a side note, if you have the tach, TRA's restoration guide says at that same commission number the tachometer was changed so rather than have a red line at "red line" the entire 5 to 6,000 RPM sector was shaded red.
Lou Metelko
Auburn, Indiana