I have the cleava made Shop-Vac style machine with filter and bag option, I found that the Kirby bag fits in there just fine and the generic hepa are pretty affordable filter never gets dirty suction doesn't drop
I think also much of that dirt internally could be contributed to the extremely well priced replacement bags available everywhere with questionable filtering ability.
Actually, my aunt used to dry her hair with the Kirby! Hose on blower port The machine sitting on the oven door and then the oven on low. Yeah she did that.
I'm going to say it's probably this very old eureka, although I do have a Montgomery awards relabeled Hoover upright in a rust color, but I'm betting there was a few of those.
Had issues with both of my previous Kenmore bag docks in the past. My 400 series is different, has had no leakage in 2 years, still same bag, so not a lot of use, but it seems to seal better to me.