American Leather Drect has Chahin Leather tanned in Mexico in several colors. https://aleatherd.com/collections/strap-leather/products/chahinleather-pigmented-strap
Long ago I found a needle reference chart on the net that listed many obsolete systems. This list went into much more detail of needle specs than just length ,diameter, etc. Unfortunately, I found it shortly before my computer died and I didn't have it in backup. Best I remember the 16x97 was much longer than any other 16 needle and again if memory serves it was much longer than other needles with the same or similar diameter. Someone once posted a page from this list here on the forum but I can't remember who or where. One of the dealers here on the forum may have this very list and be able to help with the specs.
Hartland Tannery, one of the tanneries in the Tasman Leather Group is closing for good due to Corona virus.
https://www.centralmaine.com/2020/05/04/hartland-tannery-to-close-by-summers-end-leaving-115-out-of-work/
This may be helpful. Take note of the shuttle and bobbins. hopefully they are included with the machine. https://www.recyclart.org/restored-singer-industrial-sewing-machine/
See also: Butterfield and Stevens, New England Wax Thread Sewing Machine Company, Butterfield and Haven, William Butterfield, Wickersham's Patent Machine Boston, Massachusetts
I believe that it is some form of the New England Wax Thread Machine, see here at the top of the Smithsonian page. https://www.sil.si.edu/DigitalCollections/Trade-Literature/Sewing-Machines/pdf/sewing-machines.pdf