The revers side of the sleeve mentioned the identification of this LP as - aims LP 505 STEREO-MONO The etched identification of the matrix runout off both sides is clear as giving PIM-504-A & PIM-505-B. Could there be a printing error on the sleeve? Matrix / Runout: PIM-504-A P-1970 Matrix / Runout: PIM-504-B P-1970