That's a nice Fairfax. Before they had power nozzles, they had metal dirt containers and a flow-through motor (no cooling vents cut into the dome). Fairfax cleaners started in the very early 1960's, and have not changed the design (with the exception of a three-wire grounded cord, a by-pass motor, plastic dirt container and of course, the power nozzle) ever since. The original disposable bags did not fill the entire dirt container, instead being a 'square', that left room on the sides for the air to flow. The current bag fills the entire dirt container, so that no air can flow from the bottom or sides of the paper bag, only the top. The new style bags clogs very quickly with fine dirt. I try to use a cloth HEPA Kenmore 5055 bag in my Fairfax, it has room on the sides for air to flow out, and makes the machine clean far better. Not to mention better filtration too.