It does have Torx screws holding in the wheels which isn't original. They were originally flatblade screws.
There's also no black trim that I'm aware of on 500 series units except for emptor trays, cords, and bag guards. I believe it's still the Sirocco Tan color.
Like KirbyLux77 said, if you look on the bottom of the unit, there will be a sticker saying "Factory Rebuilt". Kirby doesn't sell a lifetime rebuild program. The rebuild is offered to anyone and is if you are the original owner with proof of purchase, then the rebuild is significantly discounted.
Post a picture of the underside and we can see when the machine was rebuilt.
