this may be a partial clue

http://www.dincum.com/articles/rival-holmes_res.html

here's something else

http://www.sewalot.com/sewing_machine_collection.htm

it looks like the town of Manchester in Britain was churning out sewing machines heavily around the date of yours. Jones machine Co. may have been the mfr.

http://en.wikipedia.org/wiki/Jones_Sewing_Machine_Company

about halfway down this page, they say that if a co. ordered more than 100 machines from Jones Co, they could have their own name on them. So yours could be from any number of mfrs.

http://www.sewalot.com/jones_sewing_machines.htm

here's history of the jones co.

http://www.ismacs.net/jones/home.html

according to this website there were lots of mfrs in that town around the turn of the century
http://www.ismacs.net/home.html
on this side of the pond, it appears there may have been mfrs in Manchester, NH around that time. There was also a man called Wm. Etsy who had patents on many sewing machines around that time.

http://books.google.com/books?id=cWIjAQAAMAAJ&pg=PA958&lpg=PA958&dq=manchester+b+1907+sewing+machine&source=bl&ots=uGheHgboQe&sig=hM_iPGooAVR8LSdwN93yr2GY1_w&hl=en&sa=X&ei=PZdxUO76POjG0QHg_IHgDA&ved=0CDQQ6AEwAg#v=onepage&q=manchester%20b%201907%20sewing%20machine&f=false

http://en.wikipedia.org/wiki/Manchester,_New_Hampshire
look under history here, they mention The Amoskeag foundry making sewing machines, active till 1935 ( not sure they were making machines then looks like they made a lot of diff. items)
Do you have a serial number anywhere on it? that should help a lot in your search.

Sorry this is a messy post, I'm trying to do 2 things at once here lol. Most of these pages have tons of pics, so if you scroll around you may find your or something similar to lead to yours. Can you post a pic of it? I love old machines & would like to see yours. Congrats, I hope you find the history of it.

Thanks so much for the info--I'll try to get a few photos up. The cast iron legs have "Manchester" incorporated into the scroll work, so they're pretty neat looking. Thanks again!

if you can find the serial number on the machine I'm sure we can closer to the real mfr. Both co's I think made it were large mfrs.