Thank you for your responses. My curiosity is purely academic.
My piano accordion is a regular 120 bass & I have recently been experimenting playing with piano music mostly because I want to get a better grip on reading & finding my base & counter base notes quickly on the accordion.
I have discovered this method to be a good exercise, providing & an excellent new dimension to learning. The sound produced at the moment is sometimes ‘off’, but, I am confident that once my reading ability is proficient enough, I will have the capacity to experiment with improvisation in order to achieve the ‘flow of musicality’ & sweetness of sound, which I so desire.