I suspect the Hollister book will be in the next book order, along with "American Paperweights and Their makers"
I agree that NEGC and B&S weights are quite apart from SL, they developed a different style.
One design where NEGC did show an influence from SL is the pears on latticino weight,
a quite common weight, the details are different but the overall design is similiar.
I don't have photos I can use online but Selman's catalogues have a few examples.
I took some quick pics of some US weights, showing their profiles.
First pic has three NEGC's, two scrambles and one concentric.
Second pic has the NEGC concentric on the left, a latticinio scramble is supect is B & S in the middle
and a Parpoint scatter on blue on the right.
Third pic shows the NEGC concentric's base, which is almost flat.
This concentric has annealing cracks which may account for a less than perfect polish to the base.
This is just to illustrate how weights, from NEGC at least, vary quite a lot.