Nobody can know for sure. There are lots of variables. Even if we knew the model, year and where it was made, a previous owner could have switched it out. Someone experienced could guessed by looking up the original or by listening.
Are you trying to replicate the sound on a different instrument? If you are evaluating the instrument at the shop go by sound. If you don't like the sound of the tone knob turned down after you buy it, it's very inexpensive to replace.