I did a quick check with a few online parts catalogs, and what I came up with was the R65 and R80 used the same rocker covers, the R100 has a different part number, so I don't know if it will work or not.
If the parts have any part numbers on them, the BMW part numbers are : 11121263761 for the left, and 11121263762 for the right side.
With the painted covers you have, before trying a metal brush, if you can get some paint stripper, it's a lot faster, and easier on the aluminum metal.