1970 and 71 had small reflecors on the sides of the signal lights. 72 and 73 had the larger reflecors pictured here on the HL ears. By 1975 the reflectors where on the fork legs, but I'm not sure what was done in 1974.
/5 headlight ears hold the HL further away from the fork tube than the /6, as the /5 HL has the speedo in it and is much longer than the /6.
I got a set off of flea-bay for a /5 without reflector holes. I thought they were to a /6 but the left side doesn't have the bigger mounting hole for the key ignition. I have been looking for another set since... or perhaps they were from a R69?