1 See 21
2 "Mine Eyes Have Seen the Glory"? Perhaps - sadly not with best gal (6,4)
3 Supported Charterhouse pupil who's extremely garlicky, containing personal pong (7)
4 Old college principal's first aquatic animal (5)
5 Cheesy bit from broadcaster on recipe (4)
6 One works thawing ice blocks on a farm (8)
9 What it raised for Arthur 1 around the courts? (4)
13 A long letter due when? (3)
14 Novice British agent Spanish golfer's cut up (4)
15 Fleetwood perhaps taking diplomat on road (10)
16 Symbol of Sikhism a rescue vessel's sealed up (4)
18 Seduce this undersecretary, wandering about? (8)
21/1/19 Here's person of authority round Oxford with a name for puzzling (3,3,3,5)
22 Uplifting Christmases? Elgar is in favour (5,2)
24 Group absent, letting down Arthur 2 on the boards? (4)
25 Catch Kelvin King Kutting it at the Kabaret Klub! (3,3)
26 See 23 Across
28 Something to warm hands and balls up (4)