The RY5500 was not a Sebo/Windsor product, but a very close copy of the popular Windsor Versamatic (made by Sebo and a fixture in US commercial cleaning for 30+ years).
It is identical to the old Minuteman MPV upright but in orange instead of burgundy. I don't know who made it for Minuteman/Royal...but it wasn't Sebo.
We sold one or two RY5500s years ago and I remember they were troublesome. Nothing like the nearly bulletproof Sebo/Windsor on which they were based.