Observe the belt lifter. The 508 had the red Background with white lettering. This Machine has a black belt lifter with red letters. Most likely a 505 or 4c.
HAHA David! Well put. It just so happens I will be buying this tomorrow morning so the mystery will then be solved, though I talked to the seller today and per that individual, it is a 512. So we shall see....
Interesting. The nozzle plug must be a replacement or I'm color blind. zooming in with my iPad I can read a blurry Kirby written in red on a black background.
Just arrived home with the.... 512. Everything including the trim is in decent shape, some noise on the brush roller but ended up getting it for a good price indeed. And, to settle the question of the floor... The belt lifter is.... (drum roll) red.
PS - What is done to remedy brush roll noise, besides the obvious of replacement
The brushroll will most likely have Sleeve bearings, if it's sounding "dry", then you need to clean them out and oil them up (3-in-1 oil in the Blue can, NOT the Black & red one), if it's rattling, then they're probably worn out and replacement is the only option, although I'm not sure if the brushrolls for the 505-512 are available (513 to D80 used a different brushroll with the adjuster screws in the end caps, rather than them being in the nozzle)...
Can't say any more on that cos I've never fixed or used a Kirby older than my ClassicIII...