I just bought a treadle base and cabinet at a garage sale today for $15, it didn't have a machine, which works for me (I had a machine w/o a base)...... just keep looking and one will pop up if you want to convert her back to her original power source.
I have two of sphinx model 27's, both treadles and I love them, I'm also blessed enough to have two full sets of attachments, 2 original English and one German manual, and about 12 bobbins. If you can't find bobbins let me know and I'll sell you some of them. Also let me know if you need me to scan the manual for you. They are wonderful to work on, I hope you get yours back in working order!
Cheryl