I owned a Petrof upright for a few years that I bought used. It was made in 1989-1990. The person who was selling it was not the owner, he was someone who sold pianos "as a hobby" so to speak. He would find piano, purchase them, get them tuned up and in good condition and sell them at a pretty reasonable price.
But the point is, I went to see the piano when it was at in his climate-controlled piano shop, not in the home of the owner. I didn't notice any odor when I played it.
But after it was in my living room for a few days (maybe a week, I don't remember) I started to notice that it smelled like the inside of a cigar box. Not cigar smoke smell or cigarette smell, but that vaguely sweet smell that I always guessed was from the leaves?
Anyway, it was pretty subtle and not at all unpleasant. When I took the front panel off, I noticed it even more, but as soon as you replaced the panel, the aroma reduced to the point where you'd wonder if it was your imagination.
I actually wondered if the smell was from some material in the piano, glue or felt or some kind of wood.
Eventually I stopped noticing it, whether because the smell faded or my nose just got bored with the odor. But every now and then, say when the weather changed, I would notice the smell again. I kind of liked it.
I no longer have that piano. My new (to me) piano had only one owner before I got it. He was a signer and did not smoke. He had a dog, but I don't think he allowed the dog in his piano room.
This piano does not, to my knowledge, have a smell. Although I'll go check later (and probably get caught by my spouse with my head stuck in the piano sniffing, adding further fuel to his belief that I'm totally piano crazy!