The great thing about Singers is that the basics are almost always the same, or very similar. I've threaded 4 different models (1927 in a case, 1936 treadle [I think it is a 99 head], 1951 FW, and 1971 FashionMate), and the thread path was almost identical in each one. Even the light bulbs are the same! Once you have it serviced and find a manual, you'll probably be able to maintain it yourself.