First, I don't think this was done by an "engraver".
Some in cursive, Chadwick? printed, ... different styles and lettering.
William ... with his giant flaring W ... wrote his first.
Taylor started off big and well-spaced only to go ... sh.t, I'm running out of space.
Engraver wouldn't make that mistake.
These are, what OP? 7 names ? ... are they all men ?
I think you have individual signatures.
Could be important, and would help a lot if you could spell out the names.
O M G!
Langhorne Gibson is the son of Charles Dana Gibson - the creator of the iconic "Gibson Girl".
Langhorne Gibson is a possibility ... but, imagine ... if it was Irene Langhorne Gibson.
OP can answer this by turning this slightly .
If there is an I., an IRENE, or a Mrs. to the left of Langhorne, then you'd have the signature of one of the most famous women in the world at that time ... the original Gibson Girl.
If there is a MR. or nothing to the left of Langhorne, then it's probably her son, ... Langhorne Gibson.
A tidbit of info was in this, "how they met" :
The story goes that Gibson met Irene Langhorne – sister of Lady Nancy Astor -
Is the first name on this, Astor ? her sister is an Astor at a dinner in her honour at Delmonico’s in New York. She was sitting at a table next to novelist and friend of Gibson, Richard Harding Davis [ who incidentally served as the male muse for the often confused looking Gibson Man ]. That night Gibson sketched Irene’s young face and bouffant hair in his unique style for which he was making a name, and the first ‘Celebrity’ Gibson Girl was born.
I guess I'm kinda rooting for Irene, here ... so, what's to the left of Langhorne ? Is it her or their son ?