The range is being sold by a charity shop, which almost certainly means it was donated.
If most people were about to donate a range, they wouldn't bother with cleaning - they're getting rid of it because they're done with it.
The charity shop isn't cleaning it because it would have to be hooked up to power for that, and how many places have a spare 220 outlet around? Plus, someone would have to know how to set the controls, and there may or may not be a manual with it. If there isn't, charity shop employees or volunteers might easily be clueless about how to set it.
For these reasons, I think this one is explainable.
Not to take away from the stove mentioned...but I wonder what kind of stove it is sitting next to?
I remember seeing in another thread some type of stove that was also a combo heater unit and whatever is sitting next to this GE combo reminds me of that.
I not quite willing to give the donating person a pass on donating something dirty.
For one thing donating is like selling an item as most people write it off their taxes and you would never donate a dirty dress or pair of pants, I would be embarrassed to donate a range [ or anything else ] that was dirty.
A friend had that range in his place in a gated community in Vero Beach. It worked well, but the surface unit switches were labeled HI, 9,8,7,6,5,4,3,2 and LO. If they were percentages, that should bave been stated.
I belong to a local historical society, and we have yard sales three times a year to raise money for operating expenses. Some of the things we receive are absolutely filthy - I always feel so grimy after helping ready for the sales. The worst item I ever saw was an old stained toilet seat (we tossed it).