Across:
8 Kitty (POT-) for a (-A-) time (-T-) puts on old (-O) (POTATO) records (POTATO),
9 Exactitude (ACCURACY) of American (A-) university (University College Cork = UCC) upset (= reverse indicator) (UCC = -CCU-) by smutty type (-RACY) (ACCURACY),
10 Short distance (STEP) for last four characters in 3 down (‘doorSTEP’ = STEP),
11 Porter airs (porter airs) problem (= anagram indicator) (porter airs = RESPIRATOR) to one of those immune to dust (RESPIRATOR),
12 It’s a sign of stress, in a manner of speaking (ACCENT), for son leaving Constance (‘son’ leaving ‘Constance’ = ctance = ACCENT),
14 Carried out (HONOURED) prize (HONOUR-) for engineering (-E-) degree (-D) (HONOURED),
15 Bound (STRAPPED) to be in favour of (FOR) 24 down (‘cash’ = CASH) (STRAPPED FOR CASH) having no money (STRAPPED FOR CASH),
18 Fast (F-) gallop (gallop) running (= anagram indicator) (gallop = -LAGPOL-) at rear of stable (at rear of ‘stablE’ = -E) (FLAGPOLE) is bound to raise standards (standards/flags on FLAGPOLE),
20 Aggressive type (FIERCE) fends off differences (‘fends’ off ‘differences’ = ifrece = FIERCE),
22 In a manner of speaking (ENGLISH-), worker (-MAN) (ENGLISHMAN) lives in a castle traditionally (ENGLISHMAN lives in his castle, as the saying goes),
24 Turnover (= reverse indicator) in Istanbul coffeehouse (in ‘IstanBUL Coffeehouse’ = bulc = CLUB) with staff (staff/stick = CLUB),
25 Footage (NEWSREEL) of modern (NEW-) society (-S-) sounds (= homophone indicator) genuine (‘real’ = ‘reel’ = -REEL) (NEWSREEL),
26 Mock (ERSATZ) English (E-) royal (-R-) starting to study (starting to ‘Study’ = -S-) all the letters (AZ = -A-Z) over time (-T-) (ERSATZ).
Down:
1 Ned is not part of deception (‘Ned’ is not part of ‘deception’ = ceptio = POETIC) – and there’s a kind of justice in that (POETIC justice),
2 Astounded in leaving stand-up comedian (‘astounded in’ leaving ‘stand-up comedian’ = pcma = CAMP) accommodating the scouts (CAMP),
3 Bad end (‘baD’ end = D-) to poorest (poorest) spring (= anagram indicator) (poorest = -OORSTEP) (DOORSTEP) for local canvass (DOORSTEP),
4 Rules to follow (LAWS) putting up (= reverse indicator) sample of precious wallpaper (sample of ‘preciouS WALlpaper’ = swal = LAWS),
5 What the director called (ACTION) fringe movement (faction) losing the head (f) (‘faction’ without ‘f’ = ACTION),
6 Old relative (GREAT-UNCLE) of a cruel gent? (a cruel gent) Wrong! (= anagram indicator) (a cruel gent = GREAT-UNCLE),
7 Childish vehicles (SCOOTERS) for retrospections without Pinter (‘retrospections’ without ‘Pinter’ = rosectos = SCOOTERS),
13 First lady (EV-E) welcomes Guardian (Guardian -ANGEL-) leaders insulating senators (leaders ‘Insulating Senators’ = -IS-) (EVANGELISE) from convert (EVANGELISE),
14 Characters in impoverished geopolitics (characters in ‘impoverisHED GEopolitics’ = HEDGE) create a border solution (HEDGE),
16 Able (TALENTED) to drink (-ALE-) tea (T-) opening (= position indicator) good books (New Testament = -NT-) by writer (-ED) (TALENTED),
17 Spoiled (OFF-) scene (scene) trading (= anagram indicator) (scene = -ENCES) (OFFENCES) insults (OFFENCES),
19 Used to (used to) trouble (= anagram indicator) (used to = OUSTED) one of those booted out of office (OUSTED),
21 Works out (COUNTS) in cold (C-) on horses (mounts) starting off (m) (‘mounts’ without ‘m’ = -OUNTS) (COUNTS),
23 Frenchman (Monsieur = M-) is sick (-ILL) (MILL) of local disagreement (local disagreement/fight = MILL),
24 It’s cold (C-) in the forest (-ASH) (CASH) for the bucks in America (CASH).