I saw this for sale on eBay, and got to looking at it closely, where can get the white wire running the length of the house to power the power nozzle? My Royal has short in the hose somewhere, and I could do the same thing they did on this vacuum if I knew where to get the wire.
This looks like one of the earliest Power Tanks from circa 1985, model 408. In mid-1987 it was replaced by the 411, and in 1988 by the 413, and then in 1990 by the 4300.
The power nozzle is back in business. I vacuumed the whole house with it and emptied the cloth bag twice; the first time it was practically full, the second time about half full.