I was concerned as well. The Cycle Electric unit died in the first 700 miles. I eventually mounted the H-D unit to the back plate of the rectifier mount and threw the floating front plate out. I only used the two bolt holes on the H-D unit and mounted it horizontally without any drilling, bushings or bobbins. Just tight and snug to the plate. If the motor moves it moves as a unit.
It is still there and functioning after over 30,000 miles. These are very robust units and they are mounted directly to the frames of H-D bikes just like this.
Michael,
That is very helpful - many thanks. I have passed this information on to forum member Raphy, who is the person who is likely to actually be mounting and connecting up the Harley unit. I have a feeling he may have a Harley unit on his much tweaked M3W.
Wilson