Across:
1 Danish (Danish PASTRY) model (= anagram indicator) parts (parts = PASTR-) with Yankee (-Y) (PASTRY),
4 Positions for the sailors in ships (OVERSEAS) outside of Ireland (OVERSEAS),
9 It’s what many people get up to (breakfast CEREAL) in Clare? (CE-) That’s genuine! (-REAL) (CEREAL),
10 A scoop of (ICE CREAM) rice came (rice came = ICE CREAM) prepared (= anagram indicator),
12 Flame (LIGHT-) tulip, for example, (-BULB) (LIGHTBULB) brightens up the room (LIGHTBULB),
13 Finishes 6 down (‘rock music’ = MUSIC) to score (MUSIC score),
14 There’s a chance of a recovery (ALL IS NOT LOST) provided something can be found (ALL IS NOT LOST),
18 19 down (‘barber’ = BARBER) and top secret (top ‘secret’ = - S) characters in 27 across (chairs) mostly (s) (‘chairs’ without ‘s’ = CHAIR) (BARBER’S CHAIR) offering a position for those who expect cuts (BARBER’S CHAIR),
21 One (-I) endless (l) account (‘bill’ without ‘l’ = -bil = -LIB-) for a (A-) total review (= reverse all indicator) (ALIBI) of cover story (ALIBI),
22 Sounds like (= homophone indicator) Diana (“Di” = “die” = DIE) gets the part (IS CAST) (DIE IS CAST) in The Point of No Return (point of no return = DIE IS CAST),
24 Drained (BURNT-OUT) by what you might pick up in The Sun (BURN-) from ticket-seller (tout = -T-OUT) (BURNT-OUT),
25 Take turns (ROTATE) to judge (R-ATE) good books (Old Testament = -OT-) inside (ROTATE),
26 Tough type from the bakery (ROCK CAKE) introduces 6 down (‘rock music’ = ROCK) to Trim (trim/cut = p), Cork (‘cap’ without ‘p’ = CA-) and Kildare (-KE) (ROCK CAKE),
27 Meeting leaders perhaps (CHAIRS lead meetings) misrepresented (= anagram indicator) as rich (as rich = CHAIRS).
Down:
1 Freakish (PECUIAR) exercise (PE-) to take out (cut) short (t) (‘cut’ without ‘t’ = -CU-) fiction writer (-LIAR) (PECULIAR),
2 Labour (STRUGGLE) contest? (STRUGGLE),
3 Reply (REACT) to ancestor’s missing sons (‘ancestors’ missing ‘sons’ = acestr = REACT),
5 Is outspoken (VOCA-L) about supporting film (-B- film) from Universal (-U-) and it’s a sign (-ARIES) (VOCABULARIES) they offer inspiration to those with writer’s block (VOCABULARIES),
6 Notes about Cashel perhaps (notes/music about The Rock of Cashel = ROCK MUSIC) produced by composer (ROCK MUSIC),
7 Rocky (= anagram indicator) VII (VII = seven = EVEN S-) to get Oscar (-O) (EVEN SO), nevertheless (EVEN SO),
8 Print off manuscripts (‘print’ off/ away from ‘manuscripts’ = mauscs = SUMACS) for the spicy types (SUMACS),
11 The gambler’s ongoing misfortune (RUN OF BAD LUCK) to seek a seat (RUN) has nothing (O-) to do with female (F-) having no chance (BAD LUCK) (RUN OF BAD LUCK),
15 Crime figure, for instance (STATISTIC), is leading the pack (1st = -IST-) in stable (STAT-IC) (STATISTIC),
16 Untroubled (calm = CAL-M-) about a (-A-) bunch of paramilitaries (IRA = -ARI) giving up (= reversal indicator) (CALAMARI) with those battered types who came off the boat at sea (CALAMARI),
17 Time (T-) scoundrels (-ROTTERS) (TROTTERS) spread out to keep the swine on his toes (TROTTERS),
19 Is capable of giving a clip around the ears (BARBER) for hurtful remark (BARB-) in hospital (-ER) (BARBER),
20 Awful (= anagram indicator) critic (critic = CITRIC) describes what can leave a bitter taste in one’s mouth (CITRIC),
23 It’s really lazy (SLOTH) to fire off rifle shot (‘fire’ off/without ‘rifle shot’ = lshot = SLOTH).