My 1500 has screws in the top and on both sides. Easy to take the housing off. The bottom comes off by unscrewing the feet pads and two screws by the bobbin area.
If you have a self oiling machine, the manufacturer assumes you will be taking it in for check up as the manual suggests. The machine will get a good oiling or dose of silicone to last until next maint check up. The machine will not last forever with no lubrication to keep it self oiled.