I purchased a Singer 778, very similiar to your machine in 1976. I used it a lot at first then not so much while I worked. In 2009, I retired , took machine sewing Dr for refurbish, clean etc. Now my DH does it, saves me tons of money. This is a work horse machine. Since I've retired I use mine daily many times for 4-6 hrs. at a time. The main thing is to regularly oil and clean bobbin area every time you change bobbin. My only complaint is bobbin does not hold enough thread.