Thanks for the input Ian!
From what I've heard, both mounts are used. I've been looking for these 169 fog lights (both mounts) for quite some time now, and everyone kept telling me they were impossible to find!!!
The only ones I've found for sale were here on DDK, from Philip (pmjt) and he was asking 500 Euro for them. Maybe the different mount is the reason I've found these almost half price...
Anyway, if one really wants to, there's always the possibility of removing the top mount and weld a straight screw to the back of the metal box, as both the front box-frame and lenses are exactly the same – check the 169 ref on the lens!
Cheers!