The 105.012-66 had two different case types, and people all seem to want the CB case with the lines on the lugs. Some call them facets, but I prefer to think of them as facet junctions as a facet is a two dimensional area, not a line.
Anyway, whatever we call these lines, they can be hard to spot and often they are polished off. So when buying, we need to estanblish that this special characteristic is present or not as it affects the value. Here are two examples of a 105.012-66CB:
You cannot easily see the lines in this photo – but if you are looking for them, you just just make out some ghost of a line. If we tilt the angle and change the light, we can see:
Clearly now you can see the sharp junctions.
And also in this one:
So it is clear that sometimes it is not easy to see them in sellers photos.
They other thing to bear in mind is that pretty soon some bright spark will work out how to polish the junction back onto the lug…
More on 105.012 here