I've been looking at CONCERT-DISC releases, and hope someone can provide some information. There appear to be 2 series of single LP's and a series of Box sets. A popular series, lowest number I've seen is CS-20 (stereo), mono equivalents M-1020 ff. What is last (CS-53) ?? Classical series CS-201 (stereo), mono equivalents M-1201 ff. What is last (CS 261) ?? Box sets in a 500 series SP-501, mono MP-1501 ff. What is last (507) ?? Were the box sets a product of the original company, or solely from Everest ?? There are a number of series designations Audiophile Connoisseur Sound in the Round - what is the significance of these, does AUDIOPHILE have anything to do with the Audiophile label ?? Thanks! Best wishes, Thomas.