My book must differ from yours, or maybe it's user error on my part which is probably the case, but I can't seem to find all this great information. All I can find in my book is on page 125 where it lists a: "G. Suarez, Havana B/M on VT-10 ----- apparently was a tailor/dealer in uniforms" and on page 153 where it lists a "Suarz, H Habana" which I assume is the same even though the spelling differs.
All of the following information is intended for everybody here, not just Creskol.
Because the text you quoted from the book doesn't match what's in my copy of the book, it seems you've got an earlier edition of the book. Authors McGuinn and Bezelon continually updated the book, offering a new edition every 5-to-10 years or so. Each new edition had a different colored linen cover than past editions. Mine is "butternut."
On page 125 my edition says "G Suarez, Havana. B/m on VT-10 which are on a Spanish-American War frock coat. Suarez was apparently a tailor/dealer in uniforms." That gives us the time-date info on the Suarez-backmarked buttons. BTW, a "frock coat" is one style of US Army officer uniform coat.
About who made the Suarez-backmarked Cuban Army and Vermont State Militia buttons:
The info on page 153 is from the "Waterbury Button Company back die list"... which proves that company made the Suarez buttons. Due to the typo error in Suarez's name (as Suarz) in that list, I suspect the "H" instead of "G" as his first initial is also a typo-error. Those two letters are right next to each other on a keyboard.
As Creskol mentioned, the Suarez backmark info on page 125 which says he apparently was a tailor/dealer in uniforms. The book contains many other such notations, saying the name in the backmark was a tailor/clothier. and some other notations point out a "mis-used" back.
About the use of "leftover" backs:
In reading through the backmark book, I have come across more than just a couple of examples of the use of "leftover" backs... either foreign company names (like Suarez), or backs with a backmark time-date used long after that company went out of business. I can't call to mind one to give you as an example, but trust me please, they ARE in the book.
Some of the info in my post came from the Introduction pages in the backmark book. For example, it says on page vii, "There was no hard and fast rule about either including or excluding the manufacturer's name from button backs." And, "Either the merchant [buttonmaker/button-seller] or his customer, the individual clothier, could have his name placed on the backs..."
Again, Creskol, this info is for all readers here... you probably already know the info:
The ultimate proof that most backmarks tell the name of a clothier/tailor's business rather than the button-maker is that the backmark book lists over 1,000 name-backmarks, but there have been only about 50 American manufacturers of metal buttons.
There is much additional noteworthy info in the McGuinn-&-Bazelon backmark book's Introduction section, well worth the time to read.