I came across Wolfe & Wife Vintage Sewing Machines at the Grand Canadian Steampunk Expo in 2014. They travel around Ontario to shows with their vintage sewing machines and they have a repair shop in southwestern Ontario.
At the Expo, I purchased from them, for $200, a fully reconditioned and fully functioning vintage Singer Sphinx Decal treadle sewing machine. (See photo.) It gives the most perfect straight stitch and is ideal for quilting. Wolfe & Wife were very knowledgeable, showed me how to use the machine right there at the Expo, and have been extremely responsive and supportive by email to all my inquiries.
I contacted Wolfe & Wife again about my modern, portable sewing machines. I brought them my daughter's portable Brother machine for a long overdue maintenance. And, I brought them my portable Kenmore, also overdue for a maintenance. When I got my Kenmore back, at first I couldn't figure out what was different - then I realized it didn't make a terrible thunking noise any more! So, not only did they clean and oil it, but they fixed something that I didn't even know was wrong!!! They charged $45 for each machine even though one required a repair.
I HIGHLY recommend Wolfe & Wife as a source of vintage (many different eras) sewing machines, and as quality service providers.