The actual ad says they are both R60s and you can see from the cylinders that they are. Not sure how the description changed in the post here. Looks like nice project pair.
Because of the limited number of R50Ses sold in the US many dealers had R50S valve covers left in stock and were more than happy to sell them to anybody for their R50 or R60.
On my R51/3, I have /5 valve covers to give it a sportier look. To give a hint that the bike is supped up. The /5 covers fit perfectly except they are a little taller and needs a longer stud. Some people confuse my R51/3 for a R68 but I always correct them (mostly ). Pretty sure the R68/R50s valve covers don't work on the standard R60/R50 head.