Hi Tyler,
They did a run of Model 45's for about a year that had the black combination then they reverted back to green all over. I've never quite known why they did this but it's obvious that they didn't like it in the end. It looks really good when new but as time went on and the black aged it looked untidy.
As far as the Kirby Air Cleaners were concerned, they were originally a circular piece of sponge foam that was just slipped in. Later on paper units were made.
It sounds like the remnants of an old paper unit was remaining in that mower.
Cheers,
BB.
