Across:
8 Took care of it (-DID it) after (= positional indicator) Revenue (Revenue on Line = ROS) reviewed (= reversal indicator) (ROS = SOR-) (SORDID) something dishonourable (SORDID),
9 It’s a fair amount of time (half) for those expecting (half the time for those expecting a child = HALF-TERM) break from school (HALF-TERM),
10 Trump’s (trumps/outplays = CAPS) precautions lack routine (‘precautions’ lack ‘routine’ = pcas = CAPS),
11 Enjoying The Affair without the wife (CARRYING ON) making a fuss (CARRYING ON),
12 Fish (tuna = -ANUT) starters of escargots plated (starters of ‘Escargots Plated’ = ep) up – all (= reverse all indicator) (ep = PE-) (PEANUT) with type of butter (PEANUT butter),
14 Mix up (SCRAMBLE) Marcel’s (Marcel’s) production (= anagram indicator) (Marcel’s = SCRAM-LE) about a follower (‘a’ follower = -B-) (SCRAMBLE)
15 It’s a gift to those joining The Party (BIRTHDAY PRESENT) and the key to getting into The House perhaps? (21st BIRTHDAY PRESENT),
18 Rough agent heads (‘Rough Agent’ heads = RA-) up (= reverse indicator) police force (Criminal Investigation Department = CID = -DIC-) linked to gangster’s (Al Capone’s = -ALS) (RADICALS) people seeking militant reform (RADICALS),
20 Associate (associate/connect = LINK UP) left (L-) and the writer uses it (-INK-) to lose the head (s) on drink (‘sup’ without ‘s’ = UP) (LINK UP),
22 Boycott (PICKET) bar (LINE) (PICKET LINE) for not letting the workers in (PICKET LINE),
24 It’s a measure (TAPE measure) of the characters surrounding Taoiseach in Europe (the characters surrounding ‘TAoiseach in EuroPE’ = TAPE),
25 Dance (B- -ALL) around noble (peer) initially off (p) (‘peer’ without ‘p’ = -EER) his head (his ‘Head’ = H-) (BEER HALL) in foreign drinking establishment (BEER HALL),
26 Orders (EDICTS) copies of Proclamation! (EDICTS).
Down:
1 Oscar (-O-) Furlong (F-) starts (= position indicator) craze (-RAGE) (FORAGE) to go hunting (FORAGE),
2 Probabilities (ODDS) and downside to releasing wine (‘downside’ to releasing ‘wine’ = dosd = ODDS),
3 Taught (EDUCATED) by Oriental (East = E-) from old bank (-DUCAT- old gold coin) with English (-E-) director (-D) (EDUCATED),
4 Both sides with chilli vinegar (both sides with ‘CHilli vinegAR’ = CHAR) burn a little (CHAR),
5 Layperson has no son (‘layperson’ has no ‘son’ = layper = PLAYER) working in the theatre (PLAYER),
6 Initial signature (initial ‘Signature’ = S-) sound (-TONE) by two family members (ma +son = MASON) (STONEMASON) and one of The Quarrymen perhaps (STONEMASON),
7 Unsteady (= anagram indicator) Byron (Byron = BRO-YN) consuming fine (fine = -OK-) port (port/left = -L-) (BROOKLYN) in part of New York City (BROOKLYN),
13 Those too eager to find faults (NIT-PICKERS) with those looking for bugs (NIT-PICKERS),
14 Eyesores (eye sores = STYES) with distinctive appearances (styles) left (l) out (‘styles’ without ‘l’ = STYES),
16 Fantasises (IMAGINES) this is (I-S) about wise guys following star (-MAGI-) from point-to-point (North + East = -NE) (IMAGINES),
17 Thankful (RELIEVED) it’s about (RE-) piece of fiction (-LIE-) by retiring (= reversal indicator) old leader (de Valera = Dev = -VED) (RELIEVED),
19 To be precise (factual), without the introduction (f) (‘factual’ without ‘f’ = ACTUAL), it’s not fiction (ACTUAL),
21 Arrogant (UPPITY) Unionist (U-) finds Penny (penny = -P-) has regret (-PITY) (UPPITY),
23 Part of solenoid leaking (part of ‘solenoID LEaking’ = IDLE) is not working (IDLE),
24 Fit (TRIM) to serve up (= reverse indicator) in Kashmir Tandoori (in ‘kashMIR Tandoori’ = mirt = TRIM).