Spectator 2620 - Lavatch: The Right Name?

[Matakari]

Good morning, the Spectator is no walk in the park this week with Mr Lavatch! But an fascinating quest for the right name for which I think I’ve got some interesting leads. Some clues are impeding my progress for which I would appreciate your help. Many thanks in advance!

34a Better leave cycling (5) : O??GO
35a Auditor’s perceived incident (5) : S?E??
38a Child by the Spanish fence (5) : ?A???
40a It precedes the final house (4) : S??O
41a Yes, cinema’s lead star could be this? (8) : ?S??L???
20d Like dry fruit, not dates, in liquid doses, oddly (9) : ?ILI??O??
28d Cheers very softly, given jewels to hide (7) : I?P???? ( IMPEARL )
33d Against some Bohemian enticement (5) : A??N?

(PREAMBLE:Paired unclued lights are an author and his eponymous characters. Crossing letters in 7D suggest the name in the title; solvers must correct this, entering the character’s real name by changing the contents of four cells, always making real words. )

[Tilly2]

Help please. I have ended up with 30ac being costae. I changed the 'l' to 'e'.

[Neveracrossword]

Tilly2, so have I - it's in Chambers, so is fine.

[Neveracrossword]

...sorry, I should have said - it's the plural of costa, a rib bone.

[Tilly2]

Thank you, NAC.

[Neveracrossword]

Tilyy2, you're very welcome.

[Matakari]

Grateful to Floko, JJ109, NACW, for your unstinting help and guidance for a fine Spectator from which I’ve learned quite a lot, including many a new word. The Unclueds and the end game were particularly entertaining and instructive, introducing me to the thrill of discovering an author I’ve never read before! This Spectator seems to have been geared towards making up for the mild and gentle ones we’ve encountered during the past few weeks. Thanks, NACW, I’ll have a look at the Crossword Centre offering. The weekend is going to kick off a crossword fiesta with the Jumbo puzzles tomorrow followed by the ST Crossword, Mephisto, and EV on Sunday as well as the monthly Genius. Quite a lot to look forward to!
And congratulations to Cloverjo for a well- deserved Spectator win!

[Neveracrossword]

Thanks, Matakari. Enjoy your weekend of puzzles - you could always add Listener, the Sunday Telegraph Cryptic, the Sunday Telegraph Toughie and the Inquisitor from the 'i'...

[Matakari]

Thanks a lot, NACW, but I think I'll have my hands, nay my brain, full with those I've mentioned! Have a great weekend, too!

[Floko]

To Cloverjo
Congratulations on your Spectator win

[Boethius]

Thank you, jj109

[PiffPoff]

After adjusting 7D, I can't find SCEND in Chambers. Have I made a mistake in 35A?

[JJ109]

Scend is correct

https://www.collinsdictionary.com/dictionary/english/scend

[PiffPoff]

Never mind. I missed it. Doh.

[PiffPoff]

4D Number is divisible by two (5). SEVEN. Parsing?

[Neveracrossword]

S = is, 'S, common in crosswords and Even divisible.

[Neveracrossword]

... sorry, and Even = divisible by two.

[PiffPoff]

Thanks!