I modified an E3L with a band type end cover to accept the later alloy one piece part, but it involves filing the small alloy locating boss on the dynamo body flush,.............
I know you don't need to, but for others doing same, rather than file off the boss which would make it hard to locate a band if need be for future use, I decided to carve a recess in the cover with the Dremel
........and modifying or replacing the tufnol brush plate with the later type which has the internal female wire connections. Also there is no provision for the o ring which should seal the one piece cover, and you need the rubber cable entry grommet.
My body has provision for an 'O' ring, but not "the tufnol brush plate with the later type which has the internal female wire connections" , so I had an issue a year or so ago where the wires rubbed on the inside of the cover and caused a short which blew a couple of batteries (only- luckily) before I figured it out; rectified this by cutting the bottom off a perfect size plastic drink bottle and jamming it in- works so far