I recently stumbled upon an old clarinet case holding not 1, but 3 Martin Freres clarinets- looks to be all pre-WWI. Two out of the three (the A and Bb) are on the Simple System and one (the C) is on the Albert system. Any idea of what this would be worth? I am not a collector or a clarinetist (I'm a trombonist) so any and all information would be much appreciated!