12a) Close down early, having reduced margins (4) ?E?R
13d) Stand-ups release cartoon in press (5,5) ?O??? S?R?P
21a) Icicle melted around point in sun's path (8) EC???T?C - Eclectic?
23d) Semi-public team's quantity good? Left halves only (6) ?U?N?O
Your help greatly appreciated