Still with me eh? Hang on to the guardrails, it's probably going to get bumpy...

Notice that this detail from the Milky one shows the periods in a rather straight line. (weaker ones also, but one can't go by that all the time as molds get clogged with soot) The ampersand is pretty upright, weak lower left swirl and it finishes pointing toward the middle of the 2nd T. The period after the ampersand is spaced equi-distant from the 2nd T, which has a thicker vertical bar than the horizontal one. Pretty convincing to me that it's from a different mold as clogged embossing would not change the locations of the letters, just the depths. See how this lettering looks thinner? That's not proof the mold is different, but the letters' and punctuation locations don't change unless the iron is changed

Here is a picture of both insulators overlapped: [id=183426502]