I flipped it over, it's a 15. IIRC the bobbin case and hook assembly (proper terms?) is much smaller on the 115. The unpainted parts will see evaporust followed by a wire wheel and possibly polishing after. I'm not sure if the faceplate can be saved. The rust is really severe on the thread guide above the tension. I'm afraid there won't be anything left of it when the rust is gone. The back inspection plate is severely rusty too. Flaky rust is never a good sign.
I need to finish restoring the 27 that Kathyluvstoquilt here on the forum gave me and my daughter's Singer 99 before I start on this one so it's going to be a while.
I have a question: What is the proper diameter treadle belt for these machines? I see 3/16" and 5/16" belts for sale.
Or is it one of those things where I'm not likely to notice the difference?
I need them for both the 27 and the 15.
Thanks,
Rodney