4053  Phoney by Wasp

Wasp gave us an interesting challenge with a theme based on the telephone. The clues for the eight-letter entries were given in code, using the International Standard alphanumeric system used on telephones: 2 is A, B or C, 3 is D, E or F, and so on, with 7 and 9 representing four letters each.  However, each number contained a misprint.
Eight-letter words with misprinted letters shown in []
22932623 – 3d. AB[I]DANCE   
28243853 – 31a. A[R]CHDUKE     
36468836 – 1d. [U]NGOTTEN     
73222843 – 4a. PECCAVI[S]     
84373288 – 15a. THERE[O[UT
85376263 – 38a. U[S]ERNAME
86732247 – 17d. UNRE[P]AIR
86874789 – 18d. UNTRU[S]TY
The misprinted letters can be arranged to spell SPURIOUS which can be associated with the title. The unclued five-letter words are all words that can be preceded by the prefix TELE. They were 12a. POINT, 13a. GENIC, 35a. CASTS, 36a. TYPES, 2d/ VIEWS, 7d. VISOR, 27d. SCOPE and 30d. PATHS.
Across
1 A bit of mauve, anatomically? (4)
UVEA Hidden
10 Salt is upset after bigwig eats one (7)
NIOBATE I in NOB + ATE
14 Due operation: the first we had (4)
OWED O (1st letter of operation) + WE’D
16 Marine masters Irish lad (6)
SEAMAS  SEA + MAS (masters)
17 Old city with Dutch dialect (4)
URDU UR + DU (Dutch)
19 Wave to son with a friend (7)
TSUNAMI T (to) + S (son) + UN AMI
23 Channel from southeast in New York? Quite the opposite (4)
SNYE NY in SE
24 Stroke it to produce an effect (4)
TACT ‘T (it) + ACT
25 Give responsibility to America in International radio telephony (7)
INTRUST US in INT & RT
26 Mapmaker takes points around feature (4)
NOSE OS (Ordnance Survey) in NE
28 Raise river vessel discovered in sound (6, two words)
TAKE UP Homophone TAY CUP
34 At first pass, resected abnormal ureteric vessel (4)
PRAU Initial letters P(ass) R(esected) A(bnormal) U(retic)
37 Once, name call in stakes (7)
BEHIGHT HIGH in BET
39 Round the start of summer, chap is hopeful (4)
ROSY S (ummer) in ROY (a chap's name)
 
Down
4 Proceed with bill for universal treaty (4)
PACT  AC (bill) for U in PUT
5 Goddess consisting of wax (7)
CERESIN CERES + IN
6 Person who's remarkable, unique getting left out (4, two words)
A ONE A(L)ONE less L
8 Vigo's girl eats food and bones (7)
INCUDES CUD (food) in INES (a Spanish name)
9 Restore letter taken from part of a sonnet (4)
STET S(es)TET less ES
11 Flier knocks over a bowler, perhaps (4)
TAHA A HAT reversed
12 Stickler set about jumped-up gentleman (6)
PURIST SIR reversed in PUT
20 Playing these stages with Pete, to portray stereotypes (7)
STOREYS Compound anagram STEREOTYPES less anagram PETE
21 Disputing price of alternative technology? (6, two words)
AT ODDS AT + ODDS (price)
22 Clothes German with contents of bumbag (7)
MITUMBA MIT (With in German) + (b)UMBA(g)
29 Fruit from island in sound (4)
AKEE Homophone A KEY
31 Divinity Italian cast in gold (4)
AITU IT in AU
32 Desire is no good in this watchman (4)
HUER HUNGER less NG (no good)
33 Will's increase in wage cheque (4)
ECHE Hidden