So, τὸ κατὰ ψυχὴν χαῖρον ἐπὶ τῇ ... μνήμῃ "the enjoying throughout (my) mind... of the memory"
So I don't think we can make a firm body (flesh)/mind dichotomy with ΧΑΡΑ/ΕΥΦΡΟΣΥΝΗ. There seem to be more nuances going on, at least in Epicurus' use of the terms.
Could this use of KAPA be describing a whole-body-mind feeling of pleasure that occurs when a vivid mental recollection of a past significant joyous event, causes the mind to trigger the brain/body to release of the pleasure chemicals (endorphins)? Is this one of those nuances?
Good thought! I agree with Don that there isn't a sharp, technical division, they're just expressions of different qualities and varieties of pleasure, which is ultimately seen as a single concept.