I have. I would think most players who've been playing a while can id the notes on their basic accordion, especially if that's the one they learned on, at least the guys I've been around can. It seems easy on a C, but anything else seems not as easy to remember. I can remember the D just because I've tuned so many.
Knowing the notes of my accordions was pretty critical when I was learning songs in the 3rd position, it helped with the transposing since it seemed so unnatural to me to play in that position.
Bryan, you have no idea just how right you are. Time and understanding within this accordion discussion group will prove it. For those that are able to pay attention, seek, search, and decipher all of it, once it's all said and done.