Yea I'm playing on a 640 mm scale length Torres-esque guitar at the moment. I've never regretted going down to the 640. I'm actually thinking that my next guitar would be 630 or less - that was a factor that lead me to this search. I like digging these instruments up too! I found a couple other interesting threads:
Washburn - http://www.acousticguitarforum.com/foru ... p?t=352223
Bay State - http://acousticguitarforum.com/forums/s ... p?t=236012
Now right from Bay State's info comes this quote:
Bay State guitars from that era are known for their fine wood and intricate inlays and bridges although Bay State also constructed plain unadorned instruments. All guitars were gut string since, of course, steel strings were not widely known or used until the 1920’s. Of course, the guitars did not have truss rods or reinforcements of any kind in the neck.
And from a random person this quote on the Washburns:
All Washburn standard models up to 1915 were built for gut strings. If you want to PM me the serial number off the top of the headstock I may be able to give you a year of manufacture Warren.
And, I think you're right, most of these folks that still want to use steel strings are using silk and steel. There's a reference to an extra light set of steel made by Thomastik-Infeld branded as 'plectrum' strings that pull even less tension than most silk and steel sets