Old furnace cleaning trucks

[Charlie B]

I have been searching for a picture of one of the old furnace cleaning outfits that few of us will remember. I am talking about the ones that set up and the bag was the size of a small blimp that took up a couple of parking places. It was really quite a show, and of course, that was what it was, they never needed that big bag, but it was an attention getter. Anyhow, I want to model one and was hoping to find a picture so I could at least get close.
Anyone remember these things? I'm sure they were gone by the 60's
Charlie