This is a raised marking that appears on the dome of a "NO EMBOSSING" CD 112 that I have acquired. It is a Pennycuick style with the raised dot at the top of the pin hole. It also has a Continuous Drip (CD). Would anyone venture an opinion as to the mark? Is it part of an errased embossed mark or a mold irregularity?

All ya gotta do is ask:

It's hard to be certain from the photo, but I suspect that this is an example of what happens when a small hardened bit or string of glass falls into the mold before the main glob of glass is introduced and the insulator is pressed. One way to decide is that if it is embossing, it should protrude above the general surface of the dome. If it is a "bit of glass", it will be approximately level with the dome surface, and have "indentations" along it's edges. - -Paul Greaves