BMW is 'famous' for using up existing parts before swapping to new. The R65 bikes started with ATE calipers, but during the 1982 model year production run, they switched to Brembo. The parts are very similar and can use the same pads, but internally the calipers are different. The Brembos are used on all the R100, R80, bikes of the 1982-1994 period, so they are much easier to find parts for, etc.
Some parts were different between europe and north america bikes, too. But, I've never seen a 1982 R65LS that came from the factory with a smooth sided final drive (ie. not ribbed). All the advertisements, magazine articles etc. also show ribbed, so it is fairly likely that someone swapped it with a dinal drive from a 1979-1980 series R65, which were smooth. BMW did not ship any bikes with points after 1981, so I am pretty sure that your's was also swapped out if it has points now. Again, the 1979-1980 bikes did have points in a can, and many parts are interchangeable with even older BMWs, so it isn't unheard of to find points on a bike that didn't come with them. The W1318 code on your speedometer indicates that it is (or was) calibrated for a 32/9 (3.56:1) final drive. These can be changed/recalibrated by numerous shops like Palo Alto Speedometer. All the US-based 1982 bikes had mandatory 85 MPH speedometers also as standard. So, if your's is 120 MPH and has W1318 it may well have been worked on by them or similar type of shop and had a new face installed. If the speedometer was geared for the 31/9 (3.44:1) final drive the code at the bottom of the speedometer face should be "W1276".
Now, if you aren't confused yet, all BMW speedometers tend to read ~ 4% faster than you really are going (though the odometers are generally perfectly accurate if they are working). The difference in final drive ratios of 3.44/3.56 is about 4%, so the speedometer if still calibrated for a 3.56:1 final drive is probably given you a very clost to exact speed reading.
