Something odd looking about that bike. Maybe it's because it's a last-year model but the air cleaner and the front engine cover (with the bulge for the dampner) are R69S parts. The valve covers are R60 but the cylinders appear to be R50 cylinders. The R50 cylinders are flat on the front, the R60 cylinders have extended front and rear fins that form somewhat of a pointed shape. Perhaps that's the way they sold them in 1969 but still looks odd to me.
The advert certainly claims that it's absolutely stock and documents it through the original owner, so if it's NOT stock, that's a pretty egregious difference, especially at the price.
I'm not enough of a BMW guy to know which would be right and which wouldn't, though .....
Here's a picture of a stock 1969 R60/2 survivor. Note the different air cleaner, the front cover without the R69S bulge and you can just see the cylinders with the extended nubs on the front.
I've worked with BMW's for many years but must admit I've never worked specifically on a 1969 model. However, most of the pictures I've recently found online show the typical R60 components.
On the positive side the bike has the optional 'Sport' tank with the integral toolbox on the top. That tank is quite a premium. Personally, I like them better than the aftermarket Heinrich's and other monster tanks. I guess "beauty is in the eye..."