Is it the machine or the wooden parts of the treadle that need restoration, or both? Probably not affordable unless you do it yourself, even if you could find someone who would do it.
I would second Efemera's suggestion of the Facebook group, if you do Facebook. The group was started by a retired sewing machine salesman/mechanic who has a small business in, I think Lincolnshire, doing up Singer machines for sale and selling parts and so on. He offers advice on the group, and others have restored their own machines and cabinets. If you join post pictures and you will undoubtedly get advice and encouragement. Be warned though, dreadful group of enablers, you might get the bug and end up with more!