Amazing find. I can't believe the beautiful condition it's in. Was this from a collector?
Those are such well made vacuums. Everything is high quality and fits just so. Nothing about them is cheap. The round hole in the rear face allows you to plug the hose in and use it as a blower. This feature was deleted in the last couple of years that canister body was built. I use HEPA bags for a Numatic Henry in mine. You have to fold the bottom edge of the bag's cardboard end under a little to get the red bag adapter to seat, but that is a minor nuisance. You can also use a HEPA bag for a Riccar or Simplicity canister but that bag is much smaller than the Numatic bag. Even the Numatic bag is not quite as wide as the 5023/5033/E bag Kenmore sells.
Where is the red spout the bag attaches to? There is supposed to be a red spout with a flat end that slides into the slot in the bag chamber where the hose penetrates the body. I don't see it in the images. Without that it is basically impossible to get a bag to stay put. The elastic opening in the bag is supposed to fit over the spout. The flat end slides into the slot in the vacuum body, and the hose fits snugly into the inside diameter of the spout with a seal. Without that red spout, you have to finagle the bag over the end of the hose and they never seal right, and sometimes pop off during use. Been there done that. Find that red spout if you don't already have it. Good luck, I have been a couple of years trying to find one as I'm down one as well.
Store the hose laid straight and flat on the floor to preserve it. Don't hang it. Those hoses are harder than all get out to find. Preserve it carefully.
Ten foot hose, large bag capacity, great suction tools, just a happy combination of qualities. One of my favorite vacuums. Glad this one found a good home. I am looking at a more or less similar blue on on ebay for $129 and it is badly yellowed. Yours looks new. Well bought, bravo.