ACROSS

 1  and 6 Flying time for such as 18 across, possibly. (8,4)

10  See 5 down

11  See 37

12  A word of apology. (5)

13  Say something you’ve learned by heart. (6)

16  Puts one in the office, hopefully for the better. (6)

17  Letter in fancy style? (7)

18  Could create a gash to be found in 1 and 6 across. (4)

20  Like how a potential draftee doesn’t want to be placed in the continent. (4)

22  Works hard to get by, as half of 8 goes right on the little devils! (7)

23  Exploding star, which such as painters follow when they are fine. (4)

24  An added word or so, right to the point, where the choir finishes. (4)

25  Novelist, sort of red on the rise. (7)

27  Make an objection to the point reserved. (6)

29  Having ever so much affection, like Rin Tin Tin around his middle name. (6)

34  The music manuscript must be famous. (5)

37 , 35 , 11 and 36 What they are supposed to deserve is certainly equitable! (4,3,3,5)

38  Put up with what some do for the office–the sort which is wrong, and loud inside. (5,3)

DOWN

 2  Abraham’s son, or Mr. Newton. (5)

 3  Prairie wolf–sort of shy on a broken digit. (6)

 4  This nation is a sort without an example of how 2 goes with 4 twice. (4)

 5  and 10 across Behaves unpredictably–like egos, for example. (4,5)

 6  A total pain, as they say, but rather hearty around the boat. (6)

 7  Hungarian, for example. (5)

 8  What you might have to show later, when cars are wrecked. (4)

 9  What one wears to keep the light from being a bother looks like hell–pointless! (3-5)

14  One who has a refined taste for pie, sort of, to make things better. (7)

15  Hoping endlessly for an early wonder drug. (7)

16  How time passed by, when sort of pleased by it. (7)

18  Accumulating for preservation a billboard in London, for instance. (8)

19  and 21 Obtain a meal, as one may do reluctantly in the morning. (4,2)

25  One who does all the dirty work. (6)

26  What we was, according to the poor loser. (6)

28  An adopted maxim is all the word in Paris, to the very end. (5)

30  The princess of light opera gets what might follow land, or westward–in state. (5)

31  What the singing group should be filled with, if very happy? (4)

32  Goes out this way. (4)

33  Possibly neat example of a big blow-hard. (4)